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Cadillac Repair/1984 Eldorado parts


QUESTION: I am trying to replace the stoplight switch in my '84 Eldorado. It seems there is some sort of brake component just above the switch making it nearly impossible to unscrew the switch as the prongs from the switch hit the component just above it. Is there something I am not doing properly?
Also, all the dash lights are lit, however MPH, remaining fuel, are not working (displaying 0 mph and -- for the mpg range (gallons remaining seem to be working properly)).
I just purchased this car and am trying to get all the quirky things repaired. Thank you for your help!!


Actually yes, you are dong something wrong, but you would not know it. I can make the installation of the brake light switch quick and painless!

Be careful of harp edges at the bracket and use a glove to remove. Put your hand around the base with the wires still connected for extra leverage and pull and wiggle. It may break. Who cares if you are replacing. Just be careful! You will never unscrew it as you are finding. You could opt to snap it off with a channel locks too. Or, if you can get beneath the base at the bracket, you can pry it out as well. It is a plastic switch seated in metal that is not supposed to be removed intact.

The switch may have threads, but it does not screw into the bracket.
Have it connected electrically.

Take your left hand and depress brake pedal down. Take right hand and line up switch on bracket and push all the way down until button on switch hits break pedal. Release pedal and the switch will self-adjust and you are done!

The lights you are referring to are not on the dash light circuit and are on switched power. Could be a computer issue, wiring, connector or even a fuse.

I would highly recommend that if you are keeping this car and want to repair that you purchase a factory service manual for this car from Ebay or Craigs. Without it, you are working in the blind. The manual is the best tool you can have!
It will also guide you on your light problem.

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QUESTION: Thank you so much! I guess my "logical" brain kicked in because I saw "threads" and though it *must* be unscrewed.  :)
When it wouldn't budge I was thinking, "cut it off" but didn't want to make matters worse. The component just above also touches the brake pedal but had a "plunger" which also touches the brake pedal.
I will look for a service manual. The car is in excellent shape for her age, just a few "quirks" which are worth fixing. Thank you again for your time! Much appreciated! I'll work on getting that out today


You are welcome. I have owned many of them. Brake light switches are cheap and under $10.
Back in the 70's when working for a dealer I used the same logic about the threads-lol

Rip it out and install as described. The plunger self adjusts.

Do not settle for any manual other than the factory service manual for the car. It will walk you through just about any issue you have with the car.

Common issues with this car--4.1 and factory piston rist pin slop. Engine will sound like it is knocking. Don't worry about it. Standard from the factory.

Never get the aluminum engine a little bit hot. Shut it down at 220 or if the hot light comes on. I don't mean drive it down the block. SHUT the engine off! Otherwise engine is melting and there are no good junk yard engines to be had! Same goes for diesels-never overheat!

Antenna mast problem where antenna will constantly run. New antenna not needed. Mast kit for about $20 can be purchased on Internet.

Heater-A/C blower motor won't shut off with key out and will discharge battery. Module no longer available, but can be bypassed so at least one has high blower and off with no speeds.

Trunk lid pull down motor--Don't waste the money on new motor and adjust latch so it closes like normal trunk.

Steering column loosened up requiring disassembly (Have rebuilt thousands of these columns from theft and looseness). Caused by grabbing steering wheel to get in car.

These are a wonderful car, but these are the factory quirks not listed in the manual.

I have owned over 2 Cadillacs from Eldos to Allantes, Sevilles, Devilles etc. All but a Cimarron which was a Cavalier with a Cadillac badge. That was really JUNK!

Although I am a Caddy man, got a taste of a Benz now and not going back-lol

If you ever have questions on your classic, please don't hesitate to ask.

Good luck!

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QUESTION: (Sigh) Had someone try to change windshield wiper blades. He accidentally broke the drivers side wiper arm just under the pin that holds the blade. (huge groan here). I am having absolutely no luck with sites like Rock Auto, JC Whitney etc. finding a replacement. Do you have any suggestions where I may have luck finding one? (I have a couple of emails out to local junk yards but haven't heard back yet). Thanks again, so much!


My best answer is going to be a junk yard to get the correct part. Problem is that wiper arms are not a common replacement part and would cost far too much to manufacture for a select model.
If you don't know how to change the arm once you find on, I will make this simple: pull up on the arm and at the base of the arm you will see a clip. Pull outward on the clip while polling on the arm. The spring tension holding the arm to the windshield will be released. Then pull up on the arm and it will come off. You may have to pry the base evenly to release. Depends on fit..
Install: be very careful as to how you put the arm on. The broached must be lined up or you will striptease the spllines on the wiper transmission. Once properly seated, pull up on arm and press clump pack in. Arm should now have spring tension on the windshield.

Good luck!


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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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