Driver's seat only works intermittently

[Beachbum]

Lately my power driver's seat does not move. None of the 8-way positions work at all. But I hear the relay (relays?) under the seat clicking away. But then if I drive the car for a few miles it starts working again (sporadically). Any ideas?

I'm thinking it might be a bad connection between the relays and the seat motor? Or the relays themselves are bad? Any way to test them? Are they located in that black plastic box under the seat with the wires running to it? How do you remove them?

I took apart the seat switch but didn't see anything abnormal...no broken wires, bad connections, or burn marks on the PCB (printed circuit board). The 4 white switches mounted to the PCB all seem to be normal...they click in both directions, no "mushiness" that would lead you to believe that the switch was not working. There are no other components on the PCB other than the 4 switches, the 3 memory buttons, and the "set memory" button. Is there any way to check the seat switch with a continuity tester? The green switch harness (that plugs into the seat controller under the seat) has about 15-20 wires in it, I wouldn't begin to know what 2 wires to hook the continuity tester leads to in order to test each of the 4 switches on the PCB.

But then again, when I push any of the buttons, in either direction, I hear the seat controller clicking so I'm thinking that the switch is sending a signal to the controller, and that maybe it's not the switch?

This one is a real head scratcher! Any help appreciated, thanks.
--
2001 S80 2.9 (non-turbo), 155K miles

[Beachbum]

Post mortem...

It was the power seat control module (NOT the seat switch). The control module is the black box mounted under the seat. Found a used one on-line at a junk yard for $60 + $10 shipping (dealer wanted over $500). If you need to replace yours, just make sure the numbers on the control module match exactly with the replacement one.

I just plugged it in and it worked perfectly. (I disconnected the battery first...just to be safe).

Hope this is helpful.

Beachbum

[billofdurham]

Thank you for the update.

Bill.