Help with power seat parts!

Monttukani

New member
Aug 23, 2020
18
3
Finland
My car had a spontaneous short circuit all by her self last night. The power seat switch and elecrical connector are toast.
Also I tried to hotwire the seat, but it didn't move. It's now all the way back and tilted backwards.
The connector on the switch has power and ground but all other wires measure OL resistance to ground, so im guessing at this point that the power seat is also dead. Wires from the switch and under the seat look ok.
My electrical diagram is -84 but the car is -88. I have no clue if the system is different. Atleast the wire colors on the switch connector match.

I'm worried that the insurance check on monday is not able to determine the cost for repair and I will be at loss. Most likely they will push me into accepting the value of salvaged parts as compensation.
US cars are nowadays considered a special item here and there is very bad parts availability, other than basic service items and performance tuning parts.

So I'm kindly asking my fellow b-body lovers, is there a shop that has the seat assembly and switch available and will ship to europe?
I have used Rockauto for all my parts, but I cant find these items on their site. Maybe I'm just blind...

The car is -88 Caprice classic STW with 307 engine.

Sorry for all typos and grammar errors, I'm too tired right now to check everything and pretty much just shooting from hip.
 

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GoodOldsGuy

Member
Oct 20, 2020
75
8
Texas
I am not sure but your seat switch looks like the one on my car. It's a 79 Custom Cruiser and the switch is mounted on the seat not the door, but if my memory has any validity left, I think the Oldsmobile 98's and Cadillac Fleetwood and Sedan/Coupe Devilles (of that era) have the door mounted seat switches and the 6 way power seats like yours. So don't limit your search to Chevrolet stuff. My car shares a lot of stuff with C body Cadillac, Buick, and Pontiacs. So you might be able to find all that stuff if you broaden your search. Contact an old car junk yard in the states. There's enough of those cars left around they might be able to help you. CTC Auto Ranch in Denton Texas has several late 70s and mid 80s cars that would have had very similar (if not the same) set up you have. I don't know if they ship overseas and they don't have interior pictures of their cars on the website, but they might be a place to start, at least for a referral to someone that can help you. Good luck:)

P.S. It looks as though you have let all the magic smoke out of your switch. Catastrophic burning like that usually comes from a very profound short to ground. I'd be willing to bet that there's a crushed or severely damaged wire harness in the system somewhere (in addition to the obvious stuff in the door). Power seats are "always hot" on GM's of that era. Meaning they get an electric supply at all times, with or without the keys. Usually on an accessory power port on the fuse block noted as "battery". You're looking for orange or orange with a white stripe wire for the constant connection to battery power. I'd very thoroughly test and check that whole seat system before I plugged in any new switches or motors. Just my thoughts. I don't know about 1988 but the older GM shop manuals had very good wiring schematics that showed the wire gauge, the color codes of the wires and provided a good idea of where and what they connected to. Look into the book if you can. Some optional equipment wiring is noted in the Fisher Body manual and isn't in the main shop manual, but I think electric seats are in the GM shop manual for your car.
 
Last edited:

Monttukani

New member
Thread starter
Aug 23, 2020
18
3
Finland
A little update on the subject. I found out that the '88 model has the new style seat assembly with three motors, rather than one motor with a transmission that the older ones have. So my initial diagnosis was wrong. My '88 workshop manual did not have schematics for the power seat, but I was able to use '91 schematic. The seat motors and wiring are solid. That was further proven by the insurance check. They actually checked the wiring and seat motors also, which was a big surprise for me. Had to leave the car there for a day. I was able to drive the seat to a more comfortable position by jump wiring the switch connector. Still waiting for the insurance claim to get validated... I was actually considering that switch, but wasn't sure if it would fit. It's sold now, but good to know I can widen the search... Also, I'm thinking about the possibility of salvaging the switch frame and buttons and have a colleague of mine designing a new PCB inside it...

Thanks for the help and happy easter!
 

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