Power seat movement ... slow, intermittent.
 

I got a power seat at the junk yard and took it home. I was glad to see most functions worked, but the seat moved forwards and backwards slowly. It also would go forward, stop. Then if I released the button and pushed it forwards it would slowly inch again then stop.

I first thought something was stuck in the rails, so I cleaned them out. Mostly grease, some hair, wrappers.

While I was there, I brushed some rust off the front rails and used a rust converter on them. Don't be misled, the rust area was very small, 1.25x1.5 inches. The rest of the seat is in good condition.

Then, I lubricated the rails with silicon spray. Put it back in the car, hooked up power... the seat did the same thing.

I took out the seat, removed the switch control unit and opened it up. Things looked ok. I cleaned the switches with some CRC electronic cleaner and put the seat back in the car with the pcb board exposed so I could troubleshoot in the car.

Functionality had not been restored.

I'm readying the next action. Two clues

1. From my tests I noticed if I messed around with the memory buttons the behavior changed. Perhaps this was anecdotal. Each memory button worked and returned the seat to the proper position. Forwards and backwards movement behavior remained consistent, in that if I pressed the memory button again it would inch forwards / backwards a bit.

2. The seat seems to operate better going backwards than forwards.

From what I have read these are probable causes:

1. Cable is not short enough anymore - would this indicate more of an on / off issue?
2. Motor is... weak? Going bad? Not sure how these fail.

Any ideas? I took a video if that would be useful.

To be honest it sounds like lack of use and/or dirty contacts within the switches. Givethe switches some more contact clener and exercise then power it up again and see how it goes. Also check all other parts of the mechanism on the set frame, cleaning/lubing as needed.

When I press the switch I can feel the motor activate and the cable to the drive(?) on the rail move/tighten. Is that indication enough that the switch contacts are good?

I will try to clean the switches again. I hope it's merely that.

I'd love to take the rails right off to be able to clean them more thoroughly. At first review it looks like that would be... an effort. Will look into that process more to confirm.

With the extra information here, i'd say the switches are working but i'm confused about the cable you're on about. TO the best of my knowledge, there is a motor, gearbox and an output to a shaft with a pinon on each end that locates in and moves a rack on each side of the seat to give fore/aft movement.

There was a thread on here recently about a drivers seat that wouldn't move because drive had been lost to one of these pinions - can't remember if it was a failed coupling or what but you need to strip it down as far as necessary to find the mechaincal problem.

Tried to find the relevant diagram on volvopartswebstore but they've changed the navigation on it recently and it's a struggle. See what you can do :

https://www.volvopartswebstore.com/

You're looking for the electric seat base if memory serves.

odb?
 

It might or might not be the case that the Volvo scan tool/fault code reader gives out a fault code for an electric seat?
https://www.volvoclub.org.uk/faq/Int...icTroubleCodes
This link may be to a different model to yours. I'm curious about this only because I have electric seats. Which are behaving- so far...

Here's a link to a video of the behavior.
https://streamable.com/32yk7

I am prepping to put the front suspension back together, will get back to the seat later... Thanks for the replies, will respond when I get back to the keyboard again.

Can you turn your phone on its side and remake that please? Difficult to see the whole picture in portrait mode! :thumbs_up:

Here it is in landscape mode: https://streamable.com/fu227

That's a very telling video! It moves freely in all directions until you get halfway forward, then it slows pretty abruptly and won't go further forward.

That suggests one of two probable causes (although there are others), either there is carpet/matting getting in the way or the seat runners are bolted in crooked.

Check for any matting/carpet getting in thr way and then loosen (only 1-2 turns) each bolt that holds the seat to the floor. Then try moveing it forwards and backwards again.

You did make sure you got the little mushroom shaped things in the slots ok didn't you?

Ok - an update.

See this link for photos: https://imgur.com/a/6XJHu4O

One is of the seat underside, the two is pointing out cables on opposite sides of the motors.

I have the seat out and powered w/ alligator clips.

I've removed all three cables from one side of the motors, inserted pins, pulled the cable and checked for damage, applied some lubrication, and reinstalled. Then, Inserted a nice little pin I made in that last cable. Started it up. See video below for seat performance after installing 1/4" stainless steel pins for each cable (4).

I've checked the tracks for debris... looks clear but there's some sand / grit. I wonder if there's enough sand/grit/rust to bind it up?? After trying compressed air, and then some wire, I used PB blaster, carefully, and poured a little stream of water through (carefully).

It seems like in the process of extending the cables, the seat no longer moves at all forward and back - just engages and quits where it is.

Video - https://streamable.com/86tm2