Wipers run when Headlights are turned on.

1995 Jimmy, 4.3 W engine, 4x4, 4 door, 150K miles, original owner, Black in color, Grey interior, no aftermarket equipment, everything is stock, runs great, shifts great, check engine light is not on, showing no codes on scanner, and battery is fully charged.

A recent tune–up was done 3-months ago with all Delco parts. It’s been sitting more than it has been driven in the last 3-months. This problem started for no apparent reason 2-days ago. I did a search on this and other web sites and haven’t been able to find a solution for this problem.

When you turn on the headlights the windshield wipers come on and run. Turn headlights off and wipers stop and goto park position.

With headlights off, wipers work when wiper switch is activated.

With headlights on and the wipers running the windshield washers don’t squirt when activated, they only dribble.

With headlights off, washers work like they should when activated and wipers also activate along with the washers like they should.

It hasn’t rained here in 2 months, so the wipers haven’t been used lately, but they worked ok the last time they were used and seem to work ok when the headlights are off.

Anyone ever experience this type of problem?

Make sure all of the hi and lo beam headlamps, park lamps, tail lamps, stop lamps and turn signals work properly and come on to full brightness. If there's a problem, check all grounds for the lights. If the lights all work properly, check the ground at the wiper motor. Install a temporary ground wire from the wiper motor to the battery negative terminal and see if the issue changes. Check all body and engine grounds for good, clean, tight connections.

Possibly a bad ignition key switch?

i'd check all grounds first, then blame it on the multi-fuction switch, if grounds are good.

dunno if my '01 is the same, but check the mass connector at the base of the steering column as well for an possible shorts. make sure it's seated well.