: Power door locks, PS power seat, "trunk open" idiot light and Oh Yeah Fuel Gauge

12-06-10, 09:05 PM
Hi all, I am the proud new owner of my "new" Caddy. Just passed smog and I registered it today!! Drives like a boat.... and I LIKE it! Unfortunately, there are a couple of electrical issues that now have me scratching my head::hmm:

Power door locks do not work... However, I do hear the power door lock solenoid clicking down by the PS footwell
Passenger side power seat does not work
Trunk pull down does not work ( this is where it gets interesting )

Oh yeah... and the fuel gauge always reads Way Over Full and the "low fuel" indicator light is illuminated. I have read on the forum that this is most likely a ground issue but not sure. When the engine is shut down and key removed, the needle moves to somehwere around 1/4 tank?

But back to the door locks, power seat and "trunk open" idiot light... When I operate the power door lock switch or the PS power seat switches, the "trunk open" light flashes. Since the pull down motor does not work, I am feeling this is my problem with all my electrical woes except for the Fuel Gauge dilemna? Any help would be greatly appreciated. Oh and BTW, I sure hope a fuse never needs replacing....:bonkers: Do they really expect someone who is not double jointed to be able to get to the fuse panel?

12-07-10, 02:40 AM
Does your horn work? The circuit beaker for the horn is tied into the trunk pull-down, the seat controls, and the door locks.

However, if the circuit breaker were blown, there would be no power to any of the devices; the lock solenoid would not click. The trunk open indicator gets power from the GA-TRANS fuse and is grounded through the pull down motor and it being constantly on means there is something wrong with the internal switch that senses when the trunk is fully closed. The fact that the trunk open indicator goes out when you try to move the seat or lock the doors means that there is still power flowing through the system, so the fuses and circuit breaker for those system are probably good.

Your power seats and door lock might be drawing too much current. Turn the ignition to run (bulb check) and try working the seat. If the instrument panel dims or goes dark, then there may be something wrong in the wiring or solenoids that is causing the circuit to draw an exceedingly high current.

12-07-10, 07:12 PM
First off....Thanks Sven for your help!
Well, the horn does work, it does however sound a little muffled? Not what I expected it to sound like. Anyway, I got the pull down motor to work by jumping it with my test battery. To get it to screw back down involved me getting in the trunk and having a trusted friend shut the trunk softly while I had my 12v leads in place. Worked like a charm. So, my problem is that I don't have any power to the orange/black wire that feeds the motor. I checked the only plug connection I could find on the DS of the trunk and no power to the leading orange/black wire?

To clarify, when I operate the door lock switch or the PS power switches the trunk open indicator light flashes on then off as you release the switch?? Also, I did the bulb check but no dimming of lights only the trunk indicator light flashes on then off when I operate either the lock switch or PS power seat switches. I will definitely be purchasing a Service Manual on Ebay tonight! I'm not an electrical guru, but hopefully the wiring diagrams can shed some light. Could my door lock relay be bad even though it does click?

cadillac kevin
12-07-10, 07:49 PM
Oh and BTW, I sure hope a fuse never needs replacing....:bonkers: Do they really expect someone who is not double jointed to be able to get to the fuse panel?

what i did to get to the fuse panel was I took off the 2 hex screws that hold it in place. it will sit in place behind the cover, but I could not get my arm that far up to even touch the fuses on top, much less remove them. Its a total pain to do this, but its better than having to reach up in there to check fuses.
also, try laying either the front floor or seats with your feet out the open passenger door or sitting upside down in the drivers seat to reach the panel. i
(head on ground, feet over seat back)

as for your electrical problems, sounds like a grounding issue. I wish I could help more, but I have enough problems tracking mine down (totally different issues)

12-07-10, 11:05 PM
The wiring for these cars is strange... The trunk release is powered through the circuit breaker for the power windows.

But anyway, the trunk pulldown motor has an inline fuse in the wire somewhere near the pull-down unit. The same orange/black wire that powers the pull-down motor, powers the seats and the door lock relay. Maybe the inline fuse to the trunk motor is blown, which is causing everything in the circuit to be inoperable.

The door lock relay is partially powered by the Body Fuse, so you could be hearing it click because half of it is still functional. On the schematic in my book, it looks like the horns are powered by a second wire coming off the Horn Circuit breaker, which may explain why they still work.

12-08-10, 12:50 AM
Yeah, the fuse for the pulldown motor is right at the motor. Fuse is good but no power to the fuse. There is no power at the closest wiring connector which is behind the carpet on the DS of trunk. I will need to track backwards to find out where the break is. I guess I will start at the door lock relay and go from there. Thanks again and I really appreciate your help. I guess a Service Manual is a must when you are dealing with these Cads. The only ever Cadillac I have owned was an early model Escalade which was just basically a Tahoe/Yukon with Cadillac badging. I gotta say, I love this car, electrical gremlins and all!

12-08-10, 05:23 PM
The driver's seat switch is the first thing spliced into that orange and black wire.