Multi-Function Switch (MFS) and Lighting / Fuse Troubles

918Wrangler

New Member
Original poster
Joined
May 16, 2018
Messages
2
Location
Oklahoma
Hi all! I am not much of a mechanic, but that it one of the things I love about my TJ. I don't mind messing around on it as a way to learn. I am currently in the middle of a frustrating learning process.

One night as I was pulling out of my driveway I noticed my fog lights were on for no reason. I got out to turn them off and realize that they would not turn off. After some internet searching I realized this was a common issue due to the design of the multifunction switch. I pulled it out, attempted the repair, but was unsuccessful. I decided to just replace the MFS.

After replacing the MFS, all of my regular lights work, but the brakes, hazards, and turn signals do not work. After tracking some info down, again on the interwebs, I found that I have a blown #27 fuse in the fusebox under the hood. I replaced number 27 and it blew again immediately. Everything I find online talks about a short somewhere, but I just can't get past the fact that I had no fuse issues prior to switching out the MFS. Fuse #2 in the glovebox is fine. Any thoughts?
 
I would take the plug in relay that is in the old MFS and replace the one that is in the new MFS as a test to see if it resolves any of the problems. You should look at the harnesses that connect to the MFS to see if there are any problems with the wiring or the connectors.
 
Pull the flasher relay (Hopefully you pulled it out of the old MFS and moved it over) and test it.