I finally got my service manual in and I'm looking forward to digging into the many problems my C5 has and getting them resolved. One of the first things I want to try to take care of is the power seat. it works most of the time, but not quite enough. I haven't gone through all of the diagnostics in the manual yet. The manual does lack one thing though, the knowledge of many long time C5 owners, so I thought I would ask here if anyone knows anything or has dealt with this type of problem.

for the most part the power seat and power telescoping wheel work properly. On the seat, the rear verticle switch does not work. this one almost sounds mechanical. when I push the switch, the seat does not move. but I can hear something working under the seat, like a motor. it moves a certain amount of time, then stops as if it hit its limit switch. but the seat does not move. this problem occurs all of the time, the rear verticle motion has never worked. the front one does though. possibly separate problem: when I move the seat forwards and backwards it usually works. but it will randomly stop working in the middle of the moving process. I can hold the button, and the seat will move, then it will stop randomly during its travel. if I continue to hold the button, the seat stands still. if I let go of the button even for a second, then press it again, the seat resumes motion. at first it was very rare for this to happen. more recently sometimes I'll have to release and repress the switch 2 or 3 times to get the seat to move its full range of motion. I haven't tried it without sitting in it yet. the memory features seem to react the same way. I'll push a memory button to move the seat into driving position, the LED flashes as the seat moves. sometimes the seat will stop moving. the light continues to flash as if the mechanism thinks the seat simply hasn't gotten to its destination yet. it doesn't know the seat is no longer moving. The power telescoping wheel is also not working, according to the manual they are related systems. this one though is worse off than the seat. when I got the car the wheel did not work at all. then it suddenly started working again, and worked for a while, now it works sometimes. unlike the seat it won't stop and then start up again if I release and repress the switch. it just randomly stops moving and no matter what I do with the switch it won't move. then it will start working again a few minutes later. my first guess without going thorugh the diagnostic procedure in the service manual is maybe the relay? I doubt its the switch itself because 1) alot of separate switches would have to be bad and 2) because the memory features of the seat don't always work. they don't use the manual switches obviously, but I'm pretty sure they use the same relays.

the memory features sometimes to some crazy things too. I'll push the memory "1" button a few times in a row and it will sometimes move to different places. that would almost indicate a problem with the seat control module (there's a three letter acronym for it but I don't remember what that part is right now).

I'm hoping all of the problems are confined to a bad relay. its expensive, but hopefully that one part would take care of the seat and steering wheel? just wanted to see if anyone had any thoughts or experience with this type of problem. I sure hope this thing doesn't give out when the seat is in a position where I can't get the clutch down all the way!

thanks in advance if anyone has any ideas.

 

It sounds to me like bad connections somewhere. Have you had water problems inside the car? I'd start pulling apart connectors and looking for any type of corrosion on the contacts.

 

Yes I did actually. my driver's side leaked water like crazy one day when it rained hard. I found the problem and fixed it. no more leaks, but water did get in. I think that's a great place to start working on it. and that's a free fix. as soon as I can I'll get in there and take the seats out and check them out. I'll probably do more research in the service manual before I start too.

 

You might try ( if not already ) looking for anykind of obstruction in the seat tracks or behind the seats, I did run into that. good luck. cjs

 

 

Welcome to the forum.

Have you tried disconnecting the motor and applying 12 volts directly to it to see if the motor functions?