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Power seats stuck: Relay problem

38K views 6 replies 5 participants last post by  jeajack21 
#1 ·
I have had an intermittent problem, sometimes the power seats do not move. Then suddently they work again. They both do the same.

I troubleshot this last weekend and there's a relay that causes the problem. Its purpose is to give 12V to seats only when either the key has been turned ON or when either door is open. Not very clever IMO :confused: as this may cause other problems, e.g. in another thread this is the cause for power leak draining the battery slowly due to a stuck door switch, in my case it was not nice when trying to move the seat and nothing happens then.

The relay is a black plastic case relay located below the dash, left side of steering column. The problem with that in my case was a broken solder joint. Relays are notorious for that. This broken solder joint was then intermittently breaking the connection thus preventing the seat movement, after a while it would work again.

The relay can be easily changed but it can also be repaired. Just pry the case open and resolder all the joints, at least the big ones. And it may be even better than a new one.
 
#3 ·
Yes I took some pictures of the solder joint but the pics are still in my camera. The crack in the solder joint was quite narrow, hard to see with bare eyes, but big enough to circle the whole relay post in that joint. I will post that later this week once I get them out of the camera.

To access the relay, the dash front and bottom panels had to be removed, then the black relay is accessible between the steering column and the fuse box.
 
#4 ·
Picture of the power seat relay soldering

This is the picture of the relay causing power seats to stuck. The crack in solder joint was very tiny, it is a bit hard to see in the picture, you need to zoom the picture. But just resolder all the big joints that connect the relay to the PCB and the PCB to the connectors, they are most likely to crack.
 

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