1999 cherokee. 4.0 When I press the brakes they work and the rear wiper goes on. Sounds electrical but where. The switch hasn't been working properly for a year.

 

holy crap find a priest!!

 

Does your brake lights come on when you turn on the rear wiper? Sounds like there is either a short or a bad ground somewhere. I would start by looking at the wiring for the brake light switch and the wiper switch. More importantly do the cross anywhere.
Has some on cut or tapped a wire for extra lights or radio? Also is the any wire coming out of the fuse box that should't be there?

My brother once had a AMC Matador that wouldn't start unless you pushed in the cigarette lighter first. Someone had cut the ground to the starter switch and the lighter used the same ground point.

 

thats some serious anti theft
but anyway yea it sounds like the wires are crossed or a bad ground good luck finding the wires man i hate electrical problems

 

this has got to be the funniest problem i have seen on here thank you for making me laugh. And for a fix possibility you could have something screwy in your turn signal switch all of those run through that switch.

 

that's sweet I want to do that instead of fixing my lock problem lol. But yeah sounds like the wires ate crossed or tied together somewhere. I think I'd check in the back at first, or buy a Haynes manual

 

Sounds like a good anti theft device.

 

We have another problem now where the air has quit. After testing the fan blower and fuses it appears to be a wiring problem. I have a mechanic-friend helping who is going to look at wiring diagrams. Sounds like an overall wiring problem. I'll update. Thanks

 

Welcome to owning a Jeep. Although, this is the strangest electrical problem I have heard of yet.