Power seat movement ... slow, intermittent.

[Laird Scooby]

Something is jammed there!

[maxPower]

I removed the cables from the motor and manually turned each one with pliers.

The rail on the drivers side left is able to move all the way up and back. Sounds pretty gritty in there, I'd like to clean it out.

The rail on the drivers side right moves all the way back, then stops where the chair has been failing under power. It looks like I'll have to remove that to get a crack at whatever's going on mechanically. I can't see anything despite my numerous attempts with headlights, flashlights, poking and prodding etc.

[maxPower]

Originally Posted by Laird Scooby

Something is jammed there!

I think you're right.

[Laird Scooby]

Originally Posted by maxPower

The rail on the drivers side right moves all the way back, then stops where the chair has been failing under power. It looks like I'll have to remove that to get a crack at whatever's going on mechanically. I can't see anything despite my numerous attempts with headlights, flashlights, poking and prodding etc.

Think that's your answer, if it won't move by hand, it won't move under power either!. For the record, those 9xx electric seats are different to the 760 seats which is what i based my earlier comments on. Sorry for the confusion!

Bear in mind those motors are a similar size/power to wiper and/or electric window motors, have you ever tried stopping either a wiper or electric window by hand? It's not easy!

If something is stopping that rail from moving then it's obviously enough to cause a major problem. Could be a small stone/piece of large grit, or several small pieces that are bunching up at a certain point to creat a wedge.

Meticulous cleaning sounds like the only answer, testing each bit by hand so that you know it should all work together.

[maxPower]

Laird, thank you for your camaraderie through this. I am going to take the rail apart when I get back from taking my son for his Dr. checkup and I will report back on what I fix

[maxPower]

Wow.

So Instead of taking it apart I tried cleaning it again first because it looks like a mess to get apart and back together again.

After about an hours, something must have dislodged because the driver side left rail was able to be moved all the way forward!!! This was using pliers to twist the cable.

I figured I had it solved.

I aligned the track per the FAQ at brickboard and then started putting the motors back into the brackets and making sure the cables were installed properly.

After it was all back together - only the seat back works properly.

The rest of the motors make a grinding noise.

I took it apart and tried to move it again manually, things worked fine.

Hooked just one motor up (back of seat raise / lower) and tried it. Same noise, not moving. Like it's jammed. Removed the pin I put in to lengthen the cable, thinking it was interfering somehow. Same behavior.



Here's a video of what's going on: https://streamable.com/iaf0g

[maxPower]

I just tested a pattern I found. Power functions work better for just a bit after it's been disconnected from a battery. Then they work momentarily and go out.

They start to move as normally, then the motor starts making that grinding noise. The movements aren't hitting a top/bottom height, this is mid-range.

Does this make any sense?

[maxPower]

Came down this morning and this is what I saw:
https://streamable.com/l575a

Seat front up/down worked fine as expected! Then, performance went away. I'm thinking it's an electrical issue.

I investigated the computer yesterday for clues. Looked to be in great shape visually.

I'm going to the junkyard today, maybe I can grab another seat to swap out parts and continue to test.

If anyone has any ideas to deliver me from this misery.

[Laird Scooby]

Out of interest, did you test the seat in the breakers/junk yard before removing it? I'm wondering if that was part of the reason it was in there. Not sure about the laws where you live but here in the UK we have to have an MoT each year which is a safety test for want of a better expression. If the drivers seat can't be adjusted so the driver can reach the pedals etc then it's a fail point. It's possible if a similar rule exists where you are that this is why the car was in the yard and you struck unlucky with it.

That aside, the symptoms you suggest point to a fault in the ECU - the big flat box underneath the seat. If you (or someone you know) knows about electronics, it might pay to have a look inside for dry joints.

Just read your latest post about going for another seat - that might be the answer. If it works, you can swap the cushions and/or covers to get the colour scheme you want/need so colour isn't important.

[maxPower]

I found a driver seat, manual, from a 740.

Local Volvo indie told me I can swap the cushions and cover over to . Anyone disagree before I spend my afternoon on it? 😀