Wipers come on when using turn signal

[Wayne Long]

Have a 2004 tj when you turn on the left turn signal the wipers come on.

 

[L J]

Have to check multimalfunction switch.

 

[Chris]

Sounds like a failing multi-function switch.

 

[Wayne Long]

This was replaced when flasher light module was changed. this all happened after changing the headlight on the left front cause high beam was out. Everything worked ok for 4 days after the switch and bulb and light module changed, and now my daughter says this turn signal/ wiper issue

 

[L J]

If you are in a position to check, go over all of the contacts and grounds that were touched during the switch/bulb/light module change.

 

[IrishWake]

If you are in a position to check, go over all of the contacts and grounds that were touched during the switch/bulb/light module change.

Seconding this, especially if you replaced the MFS already. My wiper/turn signal issue was the loose common ground behind the driver-side headlamp assembly. The screw had wiggled it's way out.

My MFS issues were quite a bit more fun before I figured that one out... Headlights would go out permanently if you used turn signals or fog lights while the switch was hot

 

[Rustynj]

Did this get figured out?

 

[Gozo]

Did this get figured out?

Loose ground behind headlamp cowling fixed the wiper going on when left signal is on.

 

[jonny jeep]

It's the ground behind the left headlamp as Gozo says. When that ground gets bad wipers can sometimes also come on with headlamps, or when the horn is used.

The ground for the left turn, headlamps or horn gets scavenged through the wiper washer pump (which is also grounded there), feeds back through the wiper switch, and that causes the wipers to activate.