[linderpat]

OK, this is for the passenger seat, altho that does not really matter. Car is an 85 US spec.

The switch moves the seat forward, but not backwards. I got a new switch, and the problem remained. I swapped the leads at the motor, and the seat moves in the opposite direction now - backwards, but not forward. Is it the motor? I'm stumped.

[Geza-aka-Zombo]

Not familiar with the specifics of the design - Are there 3 or 2 wires at the motor? If there are 2 wires, then something else (a relay perhaps?) is changing the polarity of the connections to the motor for the direction change. If there are 3, then buzz out the wires to make sure there is continuity. The motor itself appears to be working. Best of luck.

[SeanR]

Try putting direct power to the motor in both directions and see how it reacts.

[linderpat]

Two wires Geza. Thanks Sean, I'll try that.

[Geza-aka-Zombo]

2 wires - should be a DPDT (double pole double throw) relay that switches the power. The actual relay in the car should have 2 terminals more than shown in the schematic below, as it would have 2 coils to switch the direction - nominal position would be the switch not connected to any output.

[worf]

I’m confused. The ‘85 wiring diagrams show no relay in the seat circuits. The switch is what changes polarity.

So, I’d first multimeter the switch at the first connector from the switch and then move further up-circuit if the switch tests good.

New switch that doesn’t work due to a defect is not unheard of.

(Back in the early 00’s there was a run of window switches that was soldered “backwards” during manufacturing.)

[Geza-aka-Zombo]

My apologies, I was just making an assumption - didn't get a chance to confirm it on the wiring diagram. Upon further reflection, the switch is the DPDT relay, and you are the coils.

[worf]

Right.

Occam’s Razor: wires swapped in plug connector of new switch (easy fix), wires soldered on wrong terminals of new switch (harder fix for the soldering challenged, swap wires in plug terminal for easy fix.)