98 V70 T5 Power Seat Switch is Malfunctioning

[songzunhuang]

So I have been dealing with a stuck power seat on the passenger side. The front part of the seat was stuck on the full high position. The motors seemed to be ok, and the seat was working in all other directions. So I figured that the power seat microswitch must be malfunctioning. Before buying a new switch, I thought I'd try to clean it out. It turns out it was pretty easy so I thought I'd share the process. All I had to do is spray the contact with a little electronics cleaner and it worked!

So the seat switch assembly is actually pretty easy to take off once you release the plastic zip ties holding it to the frame.

1) Look under the front edge of the seat and you'll see the control wire fasten by a few zip ties. cut those and you'll be able to release the whole assembly.

2) Lift the forward part of the seat up and then slide back to release.


From the back side, you can see the circular areas that clip onto the seat and hold it all in place.


From the picture above, you can see the location of the screws.

3) Remove the T25 screws and you can slide up the whole assembly.

4) You'll have to cut two more zip ties before you lift the switch out of the housing. Remove the switch housing and you'll see some philips head screws.

5) After you remove the philips heads screws you'll see the micro switches.

6) I used a screw driver to pop up the switch case enough the spray the cleaner inside, operated the switch a few times and then the switch worked! Since all was well, I just put it all back together. I was surprised how easy this was to do.

After doing this, I realized that I didn't need to even unplug the switches to clean it out and test it. There's plenty of slack in the wiring to leave it all in place while you clean it.

You'll need to re-fasten the wires with the all the zip ties. This re-fastening will also prevent the assembly from moving off the seat. So before you buy new power seat switches, try cleaning it out. You may save yourself some bucks and it doesn't take long to try it out.

[E Showell]

I separated the circuit board containing the microswitches from the plastic housing congaing the switch levels and found myself in possession of three exceedingly small springs. Of course I did not see where the springs came from. Anybody got any ideas on where they go so I can reassemble? Thanks.

[E Showell]

Got it. They're for the memory buttons.

[dosbricks]

Song,
This problem was addressed in this thread:
https://www.matthewsvolvosite.com/forums ... h+#p320836
Unfortunately the cleaning only lasted about one week. If you and E Showell have better success with your attempts, I and I'm sure others, would be interested to have you report back. This seems to be a fairly common problem with S/V70s.

[E Showell]

Ok. I did the "cleaning" with Deoxit Gold which is the contact conditioner to be used after the cleaner, but I ran out of the cleaner so just used the conditioner. I cleaned some obvious oxidation from the circuit board at the base of one of the microswitches. I could not lift the micros covers with a screwdriver, so I just sprayed down the microswitch "columns" for want of a better term, then depressed and released the microswitches several times to work the cleaner into the switch. So far, it appears I have restored normal function to a switch that was not allowing the seat bottom to move backward on the track. So far, so good, but only have one day's experience with the repair to report on. I'll update in a month or so to report on durability of the fix.

[E Showell]

Eight days in and the seat switch is still working as designed.

[dosbricks]

Alright, I finally decided to fix this issue on the S70, or bust it up trying. We have been driving around for months with the seat about 1-1/2" too far back since I forgot and played with the presets (this is my wife's car).

The OP, Song Huang, did a good job in explaining how to remove the switch pack and spray some electrical cleaner into the switch. But that didn't even get mine temporarily working to move the seat forward and reset the memory. I had to take the cover completely off the micro-switch and physically clean the contacts. So starting where Song left off:

1. To get the cover off the offending switch, insert a very thin flat tip screwdriver into the slots on top where the ends of the latch tabs are showing. Insert it on the outside of the tab so it wedges the tab inward toward the switch control stalk. Then pry up on the outside edge of the cover where it meets the lower half to raise it slightly. Then repeat on the other side of the switch. Now the cover is released and can be worked off. Don't worry about anything flying out or falling off--the lower half securely contains the switch in its entirety. The only thing that needs to be kept track of are the springs under the memory buttons and they are back on the switch-pack face, not on the circuit board/micro-switch set you're working on.

2. First orientate the switch panel and determine which side of the problem switch is not working, but clean both sides. I tried closing the switch on some fine sandpaper to clean the contacts but that didn't do it. Note: you can test your efforts by hand holding the removed circuit-board/switch-set with the wiring plug under the seat inserted just enough to make contact without locking its tab.

3. So back at the workbench, I scraped the contacts with an X-acto knife--the point of which is the only thing small enough to get in there. Surprisingly that also failed. So I got out a magnifying glass and an LED book light which I could position over the switch to see how this thing worked (they don't call them micro for nothing). The back end of the pivoting contact forms a third point of conductivity. I ran the X-acto tip up and down both sides of that shouldering it aside slightly and....

Ta Da! seat moves forward. Spray with contact cleaner and snap the cover on the switch. install everything in reverse.

Now all the seat functions are working and the memory positions are reset in case something else gets funky. Zero cost and a couple hours of fiddling. Perhaps this info will save someone time getting to the root of the problem.

I realize it's impossible to visualize all this, but it becomes clear once you are looking at it. Anyway, I believe the area of the switch in question is too small to get a decent photo of it.
Just don't break anything and you won't need to PM me to vent about it!

dos

[rspi]

Nice. I have one messed up now, I'll see if I can take any pics. These new camera's allow you to pinpoint a focus area.

[dosbricks]

I'm reviving this thread to report that after all the typing I did in my above 12/26/15 post and all the fiddling I did with the micro thingy contacts, the seat forward switch tapped out again.

So now that we have a pull-a-part JY in our area, I pulled a seat control from a '00 S70 and tested it in the parking lot. Problem solved for now anyway, and the cost was $5.75 + tax.

[erikv11]

Even after all that typing, unfair!!!

Thanks dos for posting it up for the archives.