[Brian]

i bought my car a year ago and the drivers seat was a mess.

one of the power switches was bad. the p o had tried to fix it and ended up breaking it.

so i had to order a new one for over a hundred bucks.

should have known the other switch was on it's way out, too.

after tackling the window switches a few weeks ago, i figured i'd try and fix the seat switch the same way.

it worked!!!

saved a bunch of bucks, too.

anyone out there who has a seat switch that doesn't work well, you can remove it from the car, take it apart, clean the contacts and put it all back together again.

the hardest part is removing the seat, and that's not too awful.



just be careful, if you do this, to not lose any of the little parts inside the switch when you dismantle it. i'd suggest taking it apart inside a ziplock bag or something, because little parts may go flying.

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[GuardsRedCoupe]

I did this same repair when I bought my car. Used sandpaper to shine the contacts back up.

If someone's power seats aren't working, I'd make this fix my first assumption. If you pull off the motor wiring, you might see the voltage from the switches. This happened to me, so I figured the switches were fine. Not the case; the voltage was there, but the current was not sufficient to drive the motor.

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[rhudeboye]

And that takes care of problem #7 http://www.968forums.com/index.php?showtop...075&#entry24075



I LUV this board.

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[wrlee]

I'd meant to write this up a few days ago, immediately after I did the seat switch overhaul, and I'd wished I'd taken pictures to post here. Here are some of what I remember (I probably won't have time to write everything right now):



GENERAL NOTES

- The switches are not removable from their harnesses (for reasons I will never understand, they are soldered in).

- The harness for the front switch is different from that of the rear switch. The rear switch has a plastic connector for the gray and black wires that plugs into a cable that operates the seat back inclination. (gray & black on the passenger side--I haven't been able to get the driver's seat out yet).

- The switches can be dismantled, but they contain 5 springs, 4 ball bearings, a plastic part and 1 spring loaded metal piece that can all fall apart once the switch is opened. Since there is not enough slack to pull the switches out and hold the switch horizontal, it will be impossible to replace the switches with the seat in place (unless you are able to break the zip ties underneath first).

- On all 4 switches (two paddles for each seat), it seems it is the top-most switch contact within the switch that goes bad most easily. On the drivers side that would be forward moving position and the passenger side, that would be rearward movements.

- In theory, it might be possible to replace the switches without removing the switches and their harnesses, but you'd have to (1) be extremely familiar with how everything is positioned and plugs together (2) have extremely small, facile hands and (3) have great eyesight that can see in dark places and at odd angles (easier with a great set of mirrors). I might have to do that for the driver's side since I cannot get my seat to move far enough forward to remove the seat bolts!

- Because you're reading this, your seats do not operate properly. You might need to short out the switch contacts to operate the seat, before removing it. See directions below.



HOW THE PADDLE SWITCH WORKS

There are actually four switches inside each paddle "switch-assembly." The switches operate in pairs for each motor to operate the motor in the forward and backward direction to control the seat. In the paddle's resting position, there is a negative circuit through all four switches. (Pressing the paddle in one direction operates the switch that is on the opposite side of the assembly). When activating a switch, its negative circuit is opened and its positive circuit is closed, driving the motor to which it is connected--to move the motor in the opposite direction, the opposing switch closes its positive circuit.



Positive power is provided via the red wire, negative through the brown. The black and the gray wires operate in pairs to one motor and the green/black and purple/black to the other.



The failure seems to be the result of the micro arcs from the switch's opening and closing that occur over time, tainting the face of the contact. The degraded contacts result in increased electrical resistance that builds to the point of either not providing enough positive power to the motor or not closing the circuit at all. Once the switch-assembly is opened it should be pretty obvious which switches are "burnt."



OPERATING THE SEAT WITH BROKEN SWITCHES

This involves a fair amount of dexterity since you have to operate the switch in the proper direction while closing the corresponding circuit (bypassing the bad switch inside the assembly). If you are not able to do this or you short the wrote connectors, you can probably blow the fuse, so you might want to get several extra 30A fuses before starting any of this.



1) Detach the switches.

a) Remove the faceplate by removing the two philips screws.

B) Remove the bracket that holds the two paddle switches (although there were two screw holes, only one of them had a philips screw holding the bracket in).

c) Now that the bracket is removed, each paddle can be released from the bracket, exposing the wiring on the back side.

2) To operate the seat, you need to hold the paddle in the direction desired and simultaneously short the proper lead to the positive power source (the Red lead). See below.



Corresponding Leads and Paddle Positions

Looking back at the face of the paddle as it sits in the seat, I'll identify the paddle positions as follows:

Code:

  Y2  

X1  X2  

  Y1

To activate the switch in the one of the above directions, hold the paddle down in the desired direction while simultaneously shorting the corresponding lead on the back of the switch assembly to the red (+) power source. (Be careful, I think you can easily blow the fuse if you do not hold the paddle down in the correct position or you short red to the wrong lead).

Code:

Black      X1  

Gray       X2  

Green/Blk  Y?*  

Purple/Blk Y?*

(*Sorry about the "Y?" info... I'll have to check my notes in a few weeks and update this)



So, for example, to active the X1 direction, use your three hands to simultaneously press the paddle to the left while shorting the Black lead to Red. (And don't get your left mixed up with your right as you look at the back of the switch!) (And have those extra 30A fuses ready).



REMOVING THE SEAT

1) Optionally, incline the seat-back forward so that the seat is more balanced when you carry the seat from the car.

2) Slide seat all the way backwards to expose the two floor bolts on the front of the track.

3) Using a 6mm allen wrench (using a ratchet and socket works really well, here) remove each bolt/washer on each of the front of the tracks.

4) Slide the seat forward, exposing the two pairs of 6mm bolts on the rear of the tracks.

5) Using the 6mm allen wrench, remove the pairs of bolts and washers on each track.

6) Open the door and tip the seat to the side so you can see the bottom of the seat being careful not to tension the power cable running from the floor to the seat.

7) The power lead runs to a connector block that is attached to a metal plate on the seat, facing upwards (towards the seat). The connector block can be removed from the plate by releasing the catch with a screwdriver and sliding to block until it detaches from the metal plate, but shouldn't be necessary. Carefully pry the connector block apart until they separate. This might be a bit stiff, but you should be able to do this by hand.

8) Remove the seat!



Manually Moving the Seat

The seat can be moved manually. There is a hole in the front of the seat mechanism for doing just that, using a 6mm allen wrench, but that didn't work for me and I broke the teeth off the old nylon gear in the process. So, here is a manual alternative.



There are two long screws that run along the inside of the seat rails. There is a single motor centered under the front of the seat that turns those screws. The motor's turning action is transmitted to the screws via flexible cables that bend 90 degrees, each turning the corresponding screw. The screw feeds to a bracket that is fixed to the seat. As the screw turns it pulls the bracket which, in turn, pulls the seat which slides on the seat rails.



1) Raise the front of the seat as high as it will go.

2) Under the front of the seat, remove the flimsy plastic cover (there should be screws, but my car only had one). This exposes the motor (centered, in front) that controls the forward and backward movement of the seat.

3) There are two plastic tubes that feed out of both sides of the motor that contain the flex cable that drives the screws (described above). One of the tubes feeds behind the nylon gear that doesn't really work. There are 'C' clips that hold each these tubes in place. Using a screwdriver (or two) pry these clips off--they have teeth that bite into the plastic tubing, so this is a little tricky.

4) Once the clips are removed, pull each of the tubes away from the motor until the end of the flex cable is free of the motor and the bracket. Straighten the tube and its cable co-linear with its screw.

5) Using pliers, turn each of the cables to turn the screws to move the seat in the direction desired. Alternate frequently so that one side does not move to far ahead of the other (which might cause the seat to bind). Try not to pull on the cable or the other end may pull out of the screw's end. If this happens just realign and reinsert by feel. If you are using pliers to turn the cable, you might try to avoid gripping the cable by its very end so that you do not accidentally strip its shape.

6) Once you've exposed the bolts, you can unbolt the seat (if that was the reason for going through this exercise).

7) In order to make sure the screw positions are aligned you might drive both sides of the seat to the end of its rail before inserting the cables and tubes back into the motor.

8) Snap the 'C' clips back into place.



REMOVING THE PADDLE SWITCHES AND HARNESSES

(I'll complete this later)



TESTING THE SWITCHES

(I'll complete this later)



OVERHAULING THE PADDLE SWITCH ASSEMBLY

Dismantling

1) Carefully hold the switch assembly upright, with the paddle facing upwards (with the paddle away from the pull of gravity).

2) Using a small screwdriver, release the tabs on both sides of the assembly. Use your thumbs to keep the top from springing free uncontrollably.

3) Over a table or over a bowl, slowly lift the paddle part up out of the assembly's "box."

4) Set the loose parts aside.



There are 4 ball bearings at the bottom of the houseing and 4 corresponding springs. The springs fit into the white plastic cross members that are controlled by the paddle rocker movements (the springs might be stuck in their sockets in the white plastic cross members). There is a brass center-post and a tiny spring that fits into the center-post of the plastic paddle centerpiece. One of the white plastic cross-members is loose, the other is attached to the paddle's center post.



Refurbishing the Switch Assembly

There are 4 metal contacts that are each toggled by the movement of the paddle--the contact that is opposite the paddle's direction of movement. I do not think it is posible to remove these contacts to clean them, they have to be cleaned in place.



1) Using small narrow strips of emery paper, curl the end so it can slip it between contacts of each switch.

2) Use your thumbnail to press the top of the switch to catch the emery paper between the contacts.

3) Then I pull the rough paper out to sand the face of the contact.

4) Repeat the process a couple of times.

5) Flip the paper over and sand the opposite contact.

6) Repeat for all 4 switches (emphacising the switches that look burnt or, if you've tested the switches, the ones that do not work as well).



Reassembling

(I'll complete this later)

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[wjk_glynn]

This write up is exactly what I need.



Thanks.



Karl.

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[Andre]

This is a perfect write-up, very detailed - thank you!

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[Cloud9...68]

Wow, fantastic! I was just contemplating my very long list of things that are broken on my car (see thread I started about this a couple of weeks ago), and was wondering if some of them, the broken seat in particular, were beyond hope. As it turns out, I'm taking the rest of the week off work, so hopefully this very detailed guide will knock out this very challenging (at least for me) problem. Thanks!

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[rxter]

I missed this one in a hurry to perfect my new old car. I let the PPI mech replace the switch and it cost me over 300 clams - arghhhhh.

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[PorscheDude]

Awesome post Bill.

Flash, perhaps move this yo DIY? These switch problems are going to become more common
as the cars age.

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