Power mirrors and drivers seat innoperable. Where to start?
11-04-2012, 12:57 AM
#1
Instructor
Thread Starter
Power mirrors and drivers seat innoperable. Where to start?
Hello. Just recently picked up a fairly clean '87 928 auto.
Anyways the power drivers seat will not move and the power mirrors don't work... My car has the 12 way seats and memory. I checked fuses and they look fine.
Should I clean out/replace the switches next?
Anyways the power drivers seat will not move and the power mirrors don't work... My car has the 12 way seats and memory. I checked fuses and they look fine.
Should I clean out/replace the switches next?
11-04-2012, 01:47 AM
#3
Nordschleife Master
In addition to the particulars you are hunting down, I would give SERIOUS attention to the ground points on the car. Clean them till they're shiny.
Clean also the battery posts till shiny.
May also want to cut through ground strap in the rear hatch. If not like a new penny, get another. If it is OK re-wrap with silicon tape robustly.
Here's a good post with pics to help you.
https://rennlist.com/forums/8938265-post3.html
I also post this pic of the engine controller grounds atop the bell housing. This pic is better then the one in the above post.
Clean also the battery posts till shiny.
May also want to cut through ground strap in the rear hatch. If not like a new penny, get another. If it is OK re-wrap with silicon tape robustly.
Here's a good post with pics to help you.
https://rennlist.com/forums/8938265-post3.html
I also post this pic of the engine controller grounds atop the bell housing. This pic is better then the one in the above post.
11-04-2012, 01:59 AM
#4
Rennlist Member
Basic mission is to remove the seats from the car so that you can completely checkout, clean and lubricate the seat linkages and power distrib. Seats are held be 6 socket headed metric bolts that are hidden in the frame rails, four in back, two in front on S4 car.
Seat needs to be forward, and rear lifted, to access back bolts.
Seat needs to be rearward, and front lifted to access front 2 bolts.
Memory board that routes all the power to each seat motor is, unfortunately, located under the seat.
Start by determining what level of access you have beneath it.
Its possible, using the 87 memory seat diagrams, to bypass the memory board and distribute power directly to the front and rear seat lift motors. But the connections are all, you guessed it.
Its sometimes possible to remove the cables from the motors and wind them with a drill.
Depends on access.
The boards can deteriorate and render the motors inop.
The seats can be wired to operate without the memory. The boards are expensive.
The four way rocker switches are very hard to disassemble and reassemble.
If you are lucky, they are just corroded a bit inside. Replacement might solve everything. But you still need access.
Seat needs to be forward, and rear lifted, to access back bolts.
Seat needs to be rearward, and front lifted to access front 2 bolts.
Memory board that routes all the power to each seat motor is, unfortunately, located under the seat.
Start by determining what level of access you have beneath it.
Its possible, using the 87 memory seat diagrams, to bypass the memory board and distribute power directly to the front and rear seat lift motors. But the connections are all, you guessed it.
Its sometimes possible to remove the cables from the motors and wind them with a drill.
Depends on access.
The boards can deteriorate and render the motors inop.
The seats can be wired to operate without the memory. The boards are expensive.
The four way rocker switches are very hard to disassemble and reassemble.
If you are lucky, they are just corroded a bit inside. Replacement might solve everything. But you still need access.
Last edited by Landseer; 11-04-2012 at 01:15 AM.
11-04-2012, 01:13 AM
#5
Team Owner
to add on to what Chris said the memory board can be taken apart and the solder joints reflowed this will usually result in full function being restored.
The trick is to get the seats out first,
remove the front plastic black trim cover,
you will find a port to use to run the seats back and forth,
NOTE be gentle as once you strip it out you will be up a creek without a paddle.
If you do get the seats to move you should consider cutting down an Allen wrench so it will fit under the seat edge.
NOTE I have seen a few times where the upper seat rail bolts have gotten loose and they fall down enough to jamb the seat rail,
if you suspect this then while running the motor or turning the port,
lift the seat up ,this may give the bolt head enough clearance to continue moving,
you will need two people to lift and motor
IIRC the board is under the Pass seat.
the board is memory for the mirrors and the seats.
The usual failure for the mirrors is the rocker switch,
I would take that out first ,
To take the switch apart , put it inside a plastic bag as the brass barrel at the bottom of the switch will fly out ,
You might consider as an aside you could remove the switch and spray elex cleaner into it then snap it back and forth,
this may restore function
NOTE the wire positions before you remove them
The trick is to get the seats out first,
remove the front plastic black trim cover,
you will find a port to use to run the seats back and forth,
NOTE be gentle as once you strip it out you will be up a creek without a paddle.
If you do get the seats to move you should consider cutting down an Allen wrench so it will fit under the seat edge.
NOTE I have seen a few times where the upper seat rail bolts have gotten loose and they fall down enough to jamb the seat rail,
if you suspect this then while running the motor or turning the port,
lift the seat up ,this may give the bolt head enough clearance to continue moving,
you will need two people to lift and motor
IIRC the board is under the Pass seat.
the board is memory for the mirrors and the seats.
The usual failure for the mirrors is the rocker switch,
I would take that out first ,
To take the switch apart , put it inside a plastic bag as the brass barrel at the bottom of the switch will fly out ,
You might consider as an aside you could remove the switch and spray elex cleaner into it then snap it back and forth,
this may restore function
NOTE the wire positions before you remove them
11-04-2012, 12:06 PM
#6
Instructor
Thread Starter
When I first picked up the car the seat would move, but only intermittenly. Maybe I'll be lucky and it's just bad grounds, or dirty switches.....
Sounds like this is gonna be fun.
Hopefully I can attack this within the next few days....
Thanks again everybody!!
Sounds like this is gonna be fun.
Hopefully I can attack this within the next few days....Thanks again everybody!!
11-04-2012, 12:29 PM
#7
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Err.. you said you checked the fuses and they looked fine...
Not sure what you mean by this - but if all you did was look at them - that isn't good enough - test them with an ohmmeter - you never know.
Fuses in question are 7, 20, 21, 24
Alan
Not sure what you mean by this - but if all you did was look at them - that isn't good enough - test them with an ohmmeter - you never know.
Fuses in question are 7, 20, 21, 24
Alan
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11-04-2012, 01:23 PM
#8
Instructor
Thread Starter
Thanks.
11-04-2012, 02:34 PM
#11
Instructor
Thread Starter
Ok. I found the problem with the seat after removing the front cover.... There was a 4X6" tin container crunched under the seat. I'm guessing it tugged on the wires somewhere along the line because if I jiggle the wires under the seat I can get all functions on the seat to work intermittenly....
Now I just need to remove the seat and fix the wires. I don't see how it's possible to get the 2nd bolt back out from the rear of the frame...
Now I just need to remove the seat and fix the wires. I don't see how it's possible to get the 2nd bolt back out from the rear of the frame...
11-04-2012, 02:39 PM
#12
Drifting
Be very careful of the electrical connector under the seat. It is very brittle and breaks. Make sure you hook it to the bottom of the seat so that it does not accidentally come under the rails when you put the seat down.
11-04-2012, 02:49 PM
#13
Instructor
Thread Starter
I have the seat forward and up in the back and there's no way. I'm tempted to just drill it out but would probly cause more damage in the process.....
Thanks.
11-04-2012, 02:51 PM
#14
Instructor
Thread Starter
11-04-2012, 03:02 PM
#15
Archive Gatekeeper
Rennlist Member
Rennlist Member
If you have a small flat blade screwdriver you ought to be able to gently pry up the mirror switch. A set of non-marring plastic panel tools from HF might be a better choice, however.
http://www.harborfreight.com/5-piece...set-67021.html
Alternatively, you may be able to pry out the light fixture in the lower door panel, and push up the mirror switch through that space. IIRC the opening in the door panel for the mirror switch is just above the courtesy light opening.
RE: getting the forward pair of rear seat bolts out, the seat does move far enough forward to get at them either with a stubby 6mm hex socket, or a long 6 mm ball-hex socket.
Whenever I am faced with a fastener that makes me think, HTF did they get that in there, I am forced to remember: Since the factory managed to get the seat in there in the first place, either they had a tool you don't, or they moved the seat farther that you have. One or the other. (Or both....)
That said, if the seat hasn't been out in 25 years, the first step would be to get some Kroil or liquid wrench down the threads. They can be quite tight. Make sure your hex socket is completely seated in the bolt head.
http://www.harborfreight.com/5-piece...set-67021.html
Alternatively, you may be able to pry out the light fixture in the lower door panel, and push up the mirror switch through that space. IIRC the opening in the door panel for the mirror switch is just above the courtesy light opening.
RE: getting the forward pair of rear seat bolts out, the seat does move far enough forward to get at them either with a stubby 6mm hex socket, or a long 6 mm ball-hex socket.
Whenever I am faced with a fastener that makes me think, HTF did they get that in there, I am forced to remember: Since the factory managed to get the seat in there in the first place, either they had a tool you don't, or they moved the seat farther that you have. One or the other. (Or both....)
That said, if the seat hasn't been out in 25 years, the first step would be to get some Kroil or liquid wrench down the threads. They can be quite tight. Make sure your hex socket is completely seated in the bolt head.