I have a 1988 GMC c2500 3/4 ton extended cab. My wipers stay on after the switch is turned off. To stop them I have to shut the ignition off. When I do this they stop. When I turn them on again the same thing happens. I just updated to the new style wiper motor today and the same thing is happening. Now with the new wiper with just the ignition on and the engine not started the wipers work fine and shut off fine. But as soon as you starte the engine the problem of them not shutting off comes back. Hopefully someone can direct me to the fix for this! Could it be in the turn signal switch that has the wipers with delay built in, be the problem? Thanks in advance!

 

First things first, this is an third generation f-body forum, not an 88 GMC truck forum.

Second, probably the switch, or the wiring in between the switch and the motor, as all windsheild wipers are designed to shut off when the ignition is off.

Good luck with the issue.

Locked.

CG