Technical Info / Tips & Tricks                                  Eldorado 1979-1985


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EFI Related

Final Drives & Speedometer Gears


THM-325 [M32] Gear Ratios:
2.74 1st Gear
1.57 2nd Gear
1.00 3rd Gear
2.07:1 Reverse

THM-325-4L [M57] Gear Ratios:
2.74:1 1st gear
1.57:1 2nd gear
1.00:1 3rd gear
0.667:1 4th gear
2.07:1 Revers


Delco 2000 Repair (1984/84):

While the old Bose units began to act up years ago, we're now at the stage where the factory Delco receivers are experiencing capacitor failure. To make matters worse, leaking electrolyte can damage the amplifier PCB, and if left un-repaired, can take out the right channel amp IC.

I'm by no means an expert on these, but have fixed up cold solder joints and replaced belts on them in the past. Recently I picked up a 5-band EQ model from an '85 Seville that needed a little help. Pics below.

1984/85 Symphony Sound w/ 5-Band EQ Amplifier Board loaded with capacitors Compatible Pinout for 1979-1985 Eldorado Radios

The initial issue was a bad power switch. I've heard of this happening, but it's a first for me. Alps is a reputable brand, so I can only surmise years of disuse allowed the contacts to oxidize. I was able to carefully disassemble the switch, spray in a little contact cleaner, and physically work the contacts with a pencil tip. Reassemble and good to go. Next was a noisy right channel. This is also a common issue, typically due to the axial caps for that section failing before the radials. Luckily, there was no electrolyte leakage, so it was just a matter of recapping the amp board. While I was at it, I also hit the major caps on the control and tuner board, but was careful to not blindly replace all tuner board caps as some of these are tuned circuits, and the smaller values rarely fail. Basically, if it as a large-value uF, it got replaced.

Where to get the caps? We're entering the sundown of through-hole component availability. Digi-Key has transitioned to order fulfillment through a 3rd party. Not only does it double shipping cost, but the brands carried are low-tier. You can still get quality caps such as Panasonic, but minimum requirements are 1000+ now. For roughly the same cost, I found Mouser still carries quality brands at approximately the same cost and put my order in through them. Click Here for the Mouser BOM    Note: Package size and electrical characteristics are a match but lead pitch on some caps is narrower than original. Quick work with a needle-nose.

When setting your search criteria, consider that slightly larger working voltages are now more common, are cheaper, and tend to be physically the same size (or smaller) than the old 16v caps.   

Amplifier Board Tuner Board Control / Main Board
4x 100uF @ 16v Axial 3x 100uF @ 16v Radial 1x 470uF @ 16v Radial
1x 100uF @ 16v Radial 1x 470uF @ 16v Radial 4x 100uF @ 16v Radial
2x 10uF @ 16v Radial 3x 10 @ 16v Radial
8x 4.7uF @ 16v Radial Vol Control Board
3x 470uF @ 16v Radial 1x 100uF @ 16v Radial
3x 1uF @ 16v Radial
1x 22uF @ 16v Radial
1x 220uF @ 16v Radial

Door Shenanigans

Broken door handle? Misadjusted glass? Need to swap an exterior mirror?

Is there anything as classy as slamming the door on an Eldo and hearing everything rattle around inside? If you're expecting perfection, you'll be dissapointed, but there are a few things you can do to help the situation. Before you grab your tools and dive right in, think like a surgeon. These door panels are fairly fragile due to age. Take your time. Get your tools together. And don't even think about proceeding without a panel clip pliers. $8.99 at Harbor Freight will do fine.

Pittsburgh 63699


Door Panel Removal

If nobody has been in that door before, consider yourself lucky. I tend to find broken or missing clips, wiring routed incorrectly, missing foam liners, etc. Now's your chance to make things right.

1. Start by removing the door controls. There's 1 Philips head screw on the driver's door, 2 on the passenger door (one long screw is concealed by the ashtray door). The driver's control has a slide clip on the end opposite of the screw, so carefully lift and slide until you clear the opening; the passenger side should lift right out. Then very carefully disconnect all the connectors by using a flathead screwdriver and a twisting motion. Be aware 12V is still present on the seat controls and lock switches so use some care with that screwdriver. If your exterior mirror is cable actuated, loosen the set screw to drop the 'joystick' out of the control bezel.

2. Next, using a -large- Philips head screwdriver, the blunter the better, remove the two screws behind the spring loaded grab handle. You should also find a Philips screw down in the opening where the door controls sit, remove it. Now unscrew the plasti-chrome lock knob at the top of the panel.

3. Remove the two Philips screws securing the interior door handle trim 'cup', remove the 'cup'.

4. Using the panel clip pliers, work your way around the door panel carefully popping out the clips. Take your time to avoid breaking clips...or the panel.

5. Once everything is loose, using the grab handle, lift straight up and tilt out slightly and the panel should unclip from the top edge of the door as you lift. Don't get carried away, the red/white marker light is still connected, so unplug this once the panel is free. If you have illuminated entry, there'll be a fiber optic cable plugged into that housing that should also pull straight out. The panel should now be free, so set it aside.

Assuming nobody's pitched it, there should be a wide rubber weatherstrip that hangs off the bottom of the panel, and fits a groove on the lower panel clips. These do go missing occasionally, so I like to grab them whenever I'm at a yard parting out an Eldo.

Replacement clips with the same style split head are cheap and available most everywhere. If you're in a hurry, Dorman will sell you a small pack at an inflated price at your FLAPS, or order a bunch off Amazon, ebay, etc. to keep on hand.

Foam Pad Removal

There should be a large, foam insulation pad covering the door and secured with large clips. These pads seem to get torn and tossed by shade tree mechanics, so I do grab them when I see them in the wild. These large head push clips WILL BREAK unless you use the clip removal pliers. If you need replacements, you can order a bag cheap from O'Reilly's under the guise of 'hood insulation clips'. They have a 2” head, fit a 1/4” hole and are part number 5440PK.

Note: the early cars have pads made of waste-thread insulation and thin plastic sheeting holding it all together, the later cars are die-cut foam; the plastic sheet on these goes towards the door-side.

Interior Door Handle Replacement

The interior handles are chromed pot metal, and eventually the hole where the linkage attaches on the backside will fatigue and break. They all seem to do it. Replacement is straightforward, just drill out the large rivet securing the handle (taking care not to let the scrap fall into the door), then slide the handle assembly forward and out. To my knowledge, these are not being repopped so you'll need to find a good used handle (junkyard, ebay). There's a little clip on the actuating rod that you'll need to remove, then thread the rod onto the new handle and reinstall the clip.

Rattles / Glass Adjustment

  • The linkage that connects to the interior door handle is a couple feet long. From the factory, a plastic snakeskin (like the type they put over bottles at the liquor store to keep them breaking) was installed to subdue rattling. Semi-effective when new, but the last one I worked on deteriorated to the touch. A better solution is to cut a small length of fuel line, slit it, and slide it over the rod. A pair of zip ties (get 'em tight) on the rod will keep the hose from sliding back and forth.

  • Check the bottom interior of the door for lost clips & screws, rust chunks, debris, etc. that will rattle when closed. There are a couple openings where you can get your hand in to feel around. If you have a Bose amp, removing it will get you more access. A shop vac with a length of heater hose attached to the nozzle will permit you to snake it into the door openings to vacuum out the narrow bottom.
  • Where did this debris come from? You know the spray glue the factory used between the inner and outer panels of the hood and trunk? The same was done between the door skins and the inner door guard beam. The stuff dries out, breaks free and now you've got a rattle between the two. I haven't been brave enough to address this yet, but silicone or butyl tape might work. Even a sticky backed thin foam strip in a strategic location or two might suffice if you can push out on the door skin enough to slip it in.
  • Door Glass...on frameless doors, the glass needs to 'give' a little as the edge seats into the roof rail weatherstrip. There are a couple adjustments on the top edge of the door that move coarse 'brush' heads into contact with the glass to keep it from 'flopping around'. The trick is that the glass is curved and if the brushes are too tight, the glass can bind or deflect the outer glass sweep when it's fully lowered; the brushes can also leave marks/scratches on the glass itself over multiple cycles. I suspect the factory adjustments on these were set “good enough”, but not perfect given the assembly line pace. If you have the patience, you can play around with these to take out the slop. There's also an adjustment near the bottom of the door that serves as a stop when the glass is fully lowered. I like to adjust this so the glass is just below the rubber sweep. BEFORE ADJUSTING THE sure there's no door sag.
  • How are your door pin bushings? Try lifting up on the door itself and see if there's any give. If so, its time to replace those bushings. Dorman to the rescue! But not so fast, after replacement you'll want to make sure you've taken out any door sag. A floor jack with a block of wood placed under the end of the door will take the weight while you loosen the upper hinge bolts. It may take a little trial-and-error to get the correct amount of pre-load on that door so that when unsupported, it lines up evenly with the rest of the body. Don't be afraid to loosen and adjust the striker, either. Years of use (and drag) can wear these down; the idea is to get it such that the door latches smoothly and the outer door skin is flush with the body. For these adjustments, you may want to have the window rolled down so it won't interfere. Adjust glass afterwards, if required.

Exterior Mirror / Outer Window Sweep / “Top of Door” Trim Removal

These are easy to remove/replace, once you know the ins-and-outs.

The exterior mirrors are mounted with studs and secured with a pair of nuts from inside the door. These are accessed easily by rolling the window down to its normal stop, and removing the door panel. A pair of access holes in the door structure allow use of a socket and extension to remove them. If cable operated, the cable is continuous all the way to the joystick. If a power mirror, follow the harness to its mating connector.

On the passenger side, if not in the door itself, this can sometimes be on the body side behind the kick panel that holds the trash receptacle. Note the clips in the door that keep the cable/harness out of the path of the moving glass; the upper one is a metal tab and stamped in. Some guys get so carried away replacing the mirror they forget about these.

If you need to remove the window sweep and chrome trim along the top of the door, it's secured by a series of philips head screws. The trick is that the glass in the door needs to be lowered beyond its stop to get a screwdriver to align. To do this, you'll see a bolt head adjustment near the bottom of the door (see pic above). Raise the glass normally, then remove this bolt, removing the bracket from the backside with your hand. Now you can lower the glass just far enough to reach all the screws.

Be aware, the end of this chrome trim closest to the outside door handle has body putty/butyl tape behind it making it seem like you forgot a screw. Just very carefully work the trim back and forth until it releases. A heat gun can help soften this. The reason for the putty, is that there's approximately an 1/8” gap that runs the length between the trim and the painted door top. Since this end is the one spot a lot of people grab to slam the door, putty fills the gap and takes out any trim deflection. When you go to reinstall, use a little butyl tape (available at most hardware stores) to accomplish the same thing.

It should not be necessary to remove the trim to change the sweep, but the same screws do sandwhich it into place so they have to come out.

With glass below top edge of door, trim strip screws are accessed

Screwdriver points to one of mirror studs. Note access holes.

Tip: I carry a pair of small jumper wires in my toolbox should I need to run a window down at a junkyard. Connected to a Dewalt battery, you have 12+ volts available to connect directly to the power window motor leads. Reverse polarity to run the motor the other direction.

Chimes & Buzzers

Starting in '79, there was a key-warning buzzer, and a separate seatbelt reminder chime (with outboard thermal timer). For 1982, a new chime replaced both and incorporated individual chime patterns for lights-on, seat belts, and key. It had an internal timer and circuitry to drive the seat belt light. The old style chime is easy to spot as it only has 2 wires. And yes, it uses a physical bar to strike a chime, so orientation matters. If yours produces a noticeable 'thunk' between strikes, check for deteriorating foam material designed to cushion the blow of the striker. You'll find the unit located left of the ECU under the passenger side of the dash.
Chime Comparison; early 2-wire version on bottom.

Blower Modules

Ah yes, the dreaded blower module failure. Early 80's Cadillacs use a unique system that controls the blower fan digitally based on commands from the Climate Control Head. This blower module, mounted on the heater box, is completely solid state without the usual load resistors or relay contacts of the older electro-mechanical stepped systems. It's not that these are particularly fragile parts, it's just that when they fail, they're expensive to replace, and are no longer available new. Failure modes include both 'no-function' and continuous-running, even with key off.

What folks typically forget is that it's blower motor current that stresses the module. So if you're ponying up the bucks for replacement, it's often cheap insurance to replace the motor as well (or at least measure load current when grounded directly). A shorted blower motor will cause almost immediate failure, but a blower motor that's restricted or has dry bearings can also draw excessive current, and over time, lead to overheating and module failure. I have heard of at least one individual making a board level repair on these, but as they're potted, they're quite difficult to tear down and troubleshoot.

Please note, the Fleetwood and Deville use different part numbers (though I'm curious what the difference really is). And the 80/81 is different from the 82/85.

While I don't recommend it, grounding the blower motor housing directly will cause it to operate at full power. If you've ever seen a toggle hanging under the dash and some makeshift 12 ga wire snaking its way to the heater box, that's why.

Part Number Compatibility:
  1980-81 E&K: 16014026
  1982-85 E&K: 16022156

Module on ebay for $600

Other Climate Control Parts

The '79 Climate "Head" is the old analog style, and I believe the same p/n as used on 77/78 Eldorados. There are certainly experts out there on troubleshooting this system, but I'm definitely not one of them. *Knock on Wood*, my '76 Eldo is still working fine. Poke around the CLC Forum and you'll get answers.

The 1980-85 System is digital, and while outward appearance is similar, there's quite a few different part numbers (see below). The diesel/V6 cars have a different pinout than the HT4100 cars which use the ECM for some inputs. Swapping between defog/non-defog units shouldn't cause a problem as long as they're intended for the correct year/drivetrain. A control with the rear defrost option will work on a non-defrost car, it just won't do anything.

Internally, the Climate Head has its own microprocessor and on the DEFI cars, is responsible for decoding the fuel economy data from the ECM, and driving the Fuel Data LEDs, including multiplexing.

Perhaps the most obvious design change is the addition of the Outside Temp feature in 1982, which coincided with a change to the Warmer/Cooler buttons.

When the 1980 digital system was designed, it appears the engineers focused on creating one system that would work regardless of drivetrain. The control head interfaces to the programmer as well as the blower power module. A simple on/off thermal switch tells the programmer when the engine is warmed up (122F), and it enables the blower motor, similar to how the old analog system worked. There was no 'Outside Temp' data stream to monitor, but serial data was provided from the ECM so it could decode and display Instant and Average fuel economy on the MPG Sentinel. I should note, 1980 is the only year that the fan is run at a fixed low speed when the system is set to OFF. Where this logic resides, I can't say.

In 1981, you had the diesel, 368 V864 and V6 as options on the Eldo. The thermal switch was still a thing for diesel/V6, but the 368 now reported its temp from the ECM (95F turns on the blower). It appears the Control Head & Programmer were designed to accommodate both options, though new p/n's were required (compared to '80) to do so. The pinout from the Control Head to the MPG Display is changed slightly over '80 to accommodate the new Range computer.

In 1982, Outside Temp was added, and it was decided DEFI cars would get one part number set (temp on data stream) while the diesel/V6 cars got another, which reads temp directly by the Control Head. Additionally, the Range function was integrated into the ECM, so that the Range switch input would be read by the Climate Head instead of the Range Computer, but this presented a problem as the Head connector was already fully populated. The solution was to add a single flying lead connector to the back of the Head as one of the MPG LED outputs and do a little remapping; yet another reason a new p/n was required. The Diesel/V6 cars do not have this extra single wire connector.

Climate Control Head Part Numbers:

1980: Drivetrain doesn't matter
With Defog: 16011827
Excluding Defog: 16011828

1981:  Drivetrain doesn't matter
With Defog: 1st design: 1224841
With Defog: 2nd design1224844

Excluding Defog 1st design: 1224842
Excluding Defog 2nd design: 1224845

1982-85 E/K V6 or Diesel
With Defog: 1225515
Excluding Defog: 1225517

1982-85 E/K HT4100
With Defog: 1225511
Excluding Defog: 1225513

1980/81 Style w/Rear Defog

1982-85 Style w/Rear Defog

The A/C Programmer is responsible for controlling the air mix door, opening the hot water valve via vacuum, and adjusting the mode door vacuum actuators. Removal is actually pretty easy despite first glance. The vacuum line harness is held in place by a single nut in the center. The air mix door rod snaps in/out at the top (mark the rod so you can snap it back in exactly where it was removed). And the housing is secured with two machine screws (remove glovebox line for easy access). Unplug the harness connection at the bottom and it's free.

These programmers do occasionally require repair, especially at this age. If you don't do electronics, there are places you can send them off for repair. If you do juggle a soldering iron, check for resistance across the vacuum solenoid coils. I have had coils go completely open, and I have had EMF-blocking diodes across the coils go low-Z. The diodes were easy, a couple 1N4001's and I was back in business. For the other, I scavenged coils from a parts unit. I also had a bad mix-door motor, which was easy enough to replace from said parts unit.

Note: The pinout and functionality of '80 vs '81 makes them non-compatible. The 1982-85 programmers have 3 solenoids rather than 4, though why the '82 p/n is different from '83-85 is a bit of a mystery. Compatible part numbers are listed below. On a component level, I imagine 80-85 would all be quite similar for parts if you needed to scavenge something.

According to my '83 manual, when you set the temp to 60F (max cool), the water valve closes, the recirc door opens (forcing recirc), the blower switches to high and the temp door moves to max cold. 90 (max hot) does the opposite, but recirc is disabled.

Programmer Part Numbers:

1980 E/K: 16011826

1981 E/K: 1224843

1982 E/K: 1225518

1983-85 E/K: 1226159

4-Coil Board (C-body)

E/K Programmer

Should you change any components in the system, or find things aren't operating as you'd expect, you might need to re-calibrate the programmer. Follow this link for instructions (1983).  Programmer Calibration

6-Way Power Seats...They're not all alike:

Starting in 1980, the Biarritz got power seats that used 3 motors instead of a single motor with a transmission. Seville and ETC also used the 3-motor setup, while the base Eldo soldiered on through '85 with the other setup. Because of this, the body and door wiring are different between the two as are the controls and pinouts.

One other curiosity...I pulled power seats out of an '85 Seville recently and discovered they had smaller connectors (though still 6-pin) than my 85 ETC. The '83 Shop Manual shows the Brougham using this connector type as well. Perhaps only the ETC stuck with the large connector and 3-motors?

The 3-motor logic works a little something like this...When you want to move the seat forward, the fore/aft motor is energized one way. When you move the joystick for rearward, it reverses the polarity of the two wires going to that motor. The front and rear toggles do the same for their respective motors. Simply re-arranging the wires on a 3-motor car to use a transmission-style seat isn't possible. You need to logically break out the functions.

What I did was design a circuit board that does such a thing. You can either cut the wiring on your trans-style seat and install this board in series so your body wiring stays original, or you can pick up some pigtails the next time you're at the wrecking yard and effectively make a dongle that the seat and body plug into.

3-Motor Arrangement

Transmission with single-motor

Converter Board - Testing TBD

Power Antenna Replacement/Repair (82-85 Slimline Units):

I mentioned previously that an engine swap is the perfect time to tackle that broken power antenna, because the passenger-side hood hinge has to come off to get access. (Make witness marks around the hinge bolts before removing, and watch for any washers/shims behind the hinge that might fall when you pull the bolts).

Here's the rub...the antenna can't be removed unless it's already (mostly) retracted. If you're going to swap in an entirely new assembly, you can just cut the mast right off at the top of the fender, but you can also repair these fairly easily if you can get yours out intact. The shop manual includes disassembly instructions, and references a GM repair kit. That said, I recommend the kit referenced below.

The repair kit will include a new top mast section, but you'll need to reuse your middle and lower section. I got lucky on the latest one- the mast was stuck up and unit unplugged to stop the motor from running continuously. With key on, radio off, I reconnected the two connectors and the motor again started running in an attempt to lower the mast. I was then able to carefully push down on the antenna, section by section, until the (broken) nylon cord grabbed due to friction, and got the mast mostly lowered to the point I could fish the unit out. Something you might want to try before breaking out the side-cutters.

Before installing the new mast, clean out any old grease, add a dab of fresh grease on the bottom side of the spool, clean the mast well and give it a very light oiling.

Antenna R&R

To Raise Antenna: Green +, Grey -
To Lower Antenna: White +, Green -


When you disconnect the coax connector, don't be alarmed when you unplug the two and think you've broken off the center pin; the insulator around it is spring-loaded.

With hinge removed and connectors unplugged, you'll find two 7mm bolts at the top and one 10mm bolt that secures the lower antenna bracket. The trick getting that one out is a 10mm box or Gear Wrench due to the tight clearance. Now, with some cursing and cajoling, you should be able to snake the unit out of the fender.

When re-installing, make sure you snake the wiring through the proper cutout BEFORE bolting in the assembly.

You can get a repair kit & disassembly instructions from (Cable Kit A185)

For an excellent YouTube video, see here:

Biarritz Opera Lights

The 1979-85 Opera (Coach) Lights are NOT direct incandescent, they're NOT electroluminescent, they're actually Fiber Optic. You'll find the bulbs in a holder behind the left and right trunk lining (3rd pic), which power up whenever the Park/Head Lights are turned on. This bulb looks like a 194, but it's actually a 558 with a lens molded into the glass. By their nature, these lights are dim, however you can use a directional LED replacement if you want to couple a little more light into the ends of the fiber optic strands.

Now, what typically happens is that UV, combined with turbulence going down the road, or an especially powerful car wash, disrupts the bond between the acrylic lens and the plasti-chrome body. From there, it's a short trip to bye-bye lens. NOS are no longer available from GM, and when good used ones turn up, they go for big bucks. What doesn't help is that it's not immediately apparent how these are mounted, so over-zealous parts pullers (myself included, before I got wise), try popping them out from the outside when a good one does turn up on a parts car. Besides, the slightest amount of flex breaks the seal on these anyway.

These lights are attached from the back with 'self-cutting' nuts (note pic below with uncut studs). But to get at the two nuts, you first have to remove a steel plate behind the interior sail panels, and this is held on with a series of small metric self-tappers, some of which are blocked by the headliner itself. Easy enough to remove at the u-pull-it yard, but a bit more involved on a car you care about.

NOS Replacement p/n: 913907

Note the molded tapered studs

Bulb Holder w/fiber optic lead

Bose-to-Standard Conversion:

As mentioned on the Sound System page, the '83-85 Bose setup can be hit or miss. The biggest issue these days is electrolytic cap failure which requires rebuilding the amplifier boards in each speaker enclosure. Even when working correctly, I personally prefer the sound of the UU6 Symphony Sound with 5-band EQ. The good news is conversion is fairly straightforward, and with these cars becoming increasingly collectible, the modification isn't particularly invasive.

To do the job, you'll need:

1. Two front 4x6 speakers from an Eldo, Seville, or other early 80's Cad as the Bose speakers are door mounted. (see Sound System page for new replacement)
2. Two rear 4x10 speakers (for Eldo) or 6x9 (for Seville) to replace Bose rear enclosures.
3. Delco radio of choice using the older style large "3-connector" setup. Best to verify your chosen radio works before swapping it in.
4. Your Eldo may already have unused front speaker wiring built into the dash harness; check for the connector behind your radio. If not, you'll need to create your own using a junkyard pigtail harness (white connector), or source one from a stereo adapter kit, such as this. You will need compatible ends for the speakers, which can vary depending on if you're using originals or new aftermarket, or if you prefer to solder direct. The alternative is to clip off your existing white connector and use it, though that is a permanent mod.

Before proceeding, make sure you do NOT apply power to the radio until ALL connections are made. Key-off, or better yet, negative cable disconnected.

Review the wiring diagrams below. The 1981 through 1985 standard radio wiring is the same. I suspect 79/80 is also, but if swapping in a '79 radio, the 2-pin connector is physically smaller. No idea about '80. There's no need to limit yourself to only Eldo/Seville radios. Most any Delco with the 3-connector setup will work, just keep in mind back-lighting and display color may be different.

One 4-pin connector serves the rear speakers, one serves the front speakers, and the third supplies switched 12V, Grd, Antenna Pwr Out, and Headlights 'On' input. Since these radios are ETR's, a 4th, 2-pin connector on the rear provides continuous 12V power for the clock/presets, and the dimmer signal from the headlight switch rheostat.

The Bose radio uses a very similar setup. The 2-pin connector is the same and will plug right into your new radio. The Pwr/Grd 4-pin will also plug right in. The new front speaker harness that you either made, or pulled from a donor, will connect as usual (tuck the existing connector out of the way). This leaves the rear speaker connector...

Comparing the two diagrams, you'll see the signal and ground wires for rear left and rear right are in the same terminal locations, regardless of Bose or not. Bose calls them out by letter, non-Bose by number, but no matter. You can go ahead and plug the existing connector into the radio without modification there.

At the rear, now that you've removed the amp enclosures*, you'll find a 6-pin connector for each side. All you care about is the signal and ground wire for each side; for '83 this is Light Blue/Dark Blue for right, and Brown/Yellow for left. You can either cut these wires, crimp on terminals and connect to your speakers. Or clip them on the amp-side of the 6-pin connectors so your body harness remains stock. Or search out junkyard mating connectors to use, leaving both amp harness and body harness original.

At this point, you should be ready to go. Pink wire (ckt 143) behind the radio should be unconnected (nothing to plug into), so there should be no power to the 'amplifier relay'. You can also unplug the relay for extra insurance. This is important as you want the door amps to remain unpowered. Make sure your antenna is plugged in and you're set.

*Removing the rear enclosures on an Eldo can be a pain. The package shelf needs to come out (velcro on early production, 1 screw on later prod). But to keep it from kinking, the manual recommends pulling the rear seatback first. Others have pulled the sail panels for more lateral clearance, but given the age/fragility of those, I'd consider that a last resort. Just use some care.

Transmission Mounts, R&R:

This is one of those jobs that seems easy enough, until you actually try to follow the shop manual. I mean, how hard could this be?

The early cars use steel angled pads welded to the frame, while the HT4100 cars use, what I call, donut-mounts. These mounts are bolted to the frame from the backside (outside), which means the bolt heads are inside the boxed frame member. Naturally, there are access holes in the frame rail, but they are blocked entirely by the lower plastic of the wheelhouse liner. The shop manual makes no mention of this little fact. Foolishly, I started removing one of the wheelhouses as directed, following that section of the manual, even though I knew it was going to be a multi-hour job of stripping parts to get to fastener heads. I ultimately stopped when I couldn't get to the fasteners closest to the firewall without essentially removing the fender.

Reluctantly, I resorted to the next best thing. I drilled access holes through the plastic liner, only large enough to slip a 3/8" extension through. I used a prybar to pry back the liner from the frame just enough to fit the needed socket on the backside. If the socket wants to fall into the hole in the frame when pushing the extension on, block it with a putty knife. Due to the geometry of the passenger side, 3 holes are required. On the driver side, you can get away with only 1 or 2 holes as the bottom hole is in a position where the liner can be pried back far enough to fit a ratchet and socket in behind it. Removing one or two of the lowest, most obvious wheelhouse fasteners will give you a little more flexibility as well.

When finished, you can fill the holes with black epoxy, or removable plugs.

3/8" Drive Extension 3 Holes Required for Passenger Side New Mount Installed

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