Problem: Passenger side seat-back (electric) will not go up. That is, the seat-back will recline, but will not return. Never had a problem with this seat before. When pressing the button to raise the seat, switch and (presumably) relay click, and motor jogs momentarily but stops. Holding the button, it will do this a couple of times with several seconds between, but will eventually stop altogether. I wasn't able to get any appreciable movement out of the seat this way.
I'm pretty sure I've ruled out the motor itself and the switch assembly. Best I can tell that leaves the thing in the middle - the brain box, or perhaps the little encoder on the end of the motor. If you care to read on, I've listed what I've done so far to track down the issue. Any advice or insight would be appreciated.
Troubleshooting performed so far:
1. Checked for voltage at plug leading to the motor, both directions.
2. Removed motor, checked continuity through wires between plug and motor terminals.
3. Checked seat-back cable - works both ways, no binding.
4. Applied 12V to motor - works same both directions.
5. Removed switch assembly, all looks fine, checked continuity of wires to microswitch terminals on the circuit board.
6. Checked microswitch - in the process I ended up breaking the switch free of the board (whoops!). Used that opportunity to turn the switch around in a vain attempt to find the problem. Still no luck.
7. Observed that all three Memory buttons result in the seat-back being reclined further. This is very odd because the seat was more reclined than usual (life partner wanted to sleep) when it stopped working.
There's a little encoder that bolts to the back of the motor. It drives off the back of the motor with a few small gauge wires going back to the computer. I figure that if that fails, maybe the brain-box would think that the seat is fully raised and will not let it go further? Otherwise I'm left with the computer. I looked at that thing, couldn't immediately figure out how to remove it, so I came inside, mixed myself a drink, and began typing here...
Any ideas before I go looking for new motors and computers? Are there OBDI codes for this thing ('95 850)?
Thanks for reading all the way the end of my drink. --I mean post!
-Will
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850 / Mini
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