Wipers turning on with headlights

[Mike_H]

Had a weird issue with the jeep this morning. Its cold, like low 40's and I had frost on the window. I leave for work pretty early, so it was dark too. I tried to wash the frost off the window with the washer fluid...no dice. It didn't squirt. Then I flipped my headlights on and noticed that the driver's side was very dim. The wipers were also on at this point. I went to get my scraper and tried to turn the wipers off...and realized they were already turned off.

Did a quick google search and found that the wipers share a ground with the Driver's Headlight. Bad ground will cause backfeeding through the wiper...does that make sense? I did change my headlight bulbs on Saturday and this would be the first time driving at night. I suppose its possible I don't have the connector installed properly (its an aftermarket relay harness with a ceramic connector). It can be a bit persnickety to get installed properly.

 

[Irun]

Definitely check the grounds and wiring, since you changed bulbs, at the connector. This is an extreme case, but I've seen corroded and frayed wiring on numerous TJs I've had. This is what I found when I had a similar issue, after I peeled back the insulation. Usually, I cut them and splice in a new connector.

https://www.amazon.com/dp/B07FQ6T8HP/?tag=wranglerorg-20

 

[mrblaine]

Had a weird issue with the jeep this morning. Its cold, like low 40's and I had frost on the window. I leave for work pretty early, so it was dark too. I tried to wash the frost off the window with the washer fluid...no dice. It didn't squirt. Then I flipped my headlights on and noticed that the driver's side was very dim. The wipers were also on at this point. I went to get my scraper and tried to turn the wipers off...and realized they were already turned off.

Did a quick google search and found that the wipers share a ground with the Driver's Headlight. Bad ground will cause backfeeding through the wiper...does that make sense? I did change my headlight bulbs on Saturday and this would be the first time driving at night. I suppose its possible I don't have the connector installed properly (its an aftermarket relay harness with a ceramic connector). It can be a bit persnickety to get installed properly.

If you undo the ground screw by the headlight bucket and push the horn button, the wipers will generally turn on. Make sure those grounds are good.

 

[machoheadgames]

Yeah sounds like a standard corroded ground issue probably at the driver's headlight plug since that's the one that was dim. The bad ground will certainly cause the current to seek ground in other ways which means backfeeding other accessories like the wipers or otherwise.

 

[CharlesHS]

If you undo the ground screw by the headlight bucket and push the horn button, the wipers will generally turn on. Make sure those grounds are good.

Wiring info to remember.

 

[Mike_H]

Update: I got it "fixed" at lunch. Took the ground screw out behind the light, switched the two grounds around, and it's working again... For now.

 

[Webbie]

Old Article & Fix that is STILL important for TJ Owners! - Thanks again!