Problems replacing the multi-function switch (turn signals, headlights, fog lights, & hazard lights)

Airjunky

Airjunky

TJ Enthusiast
Joined
Dec 13, 2018
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Location
Liberty Lake WA
I bought this Jeep almost a year ago & it already had a Smittybuilt bumper, LED headlights and no fog lights. I found the wiring for the fog lights tucked up underneath the radiator & figured I'd pick up some LED flood lights from HF. I got them installed & realized the PO had removed the fuse for them. Come to find out the multi-function switch that controls the headlights, fog lights, turn signals & hazard lights was worn out to the point that the fog lights would randomly come on by themselves. So I picked up a new multi-function switch from O'Reilly's (lifetime warranty). I got it installed easy enough, including the swap of the old flasher, and now the headlights & new off road lights work fine. The weird thing is that now the turn signals & hazards don't work at all. I reinstalled the old multi-function switch & same thing. WTF, they worked 10 minutes ago fine?!

So I picked up a new flasher & still nothing. At that point I found a blown 20 amp fuse in the fusebox up by the battery called MF SW. I go get another 20 amp fuse, install it with the old multifunction switch, test that everything works fine (and the off-road lights come on randomly). I pull the fuse, remove the old multi-function switch (again), and install the new one. Then I reinstall the 20 amp fuse & test the hazard lights. Immediately the fuse pops. WTF?? Bad multifunction switch out of the box?

So I return everything to O'Reilly's, get a total refund & go to Autozone. They have the same multifunction switch in stock. I get it installed with a new MF SW 20 amp fuse. I test the hazards & YES! Success!
I begin testing every scenario of lights I can think of. Heads lights work, off-road lights work, brake lights work, parking lights, turn signals....... and then I notice the rear parking lights don't work when you just have the parking lights on. WTF? Another defective multifunction switch??

I'd hate to be doing this with Rock Auto or Amazon. Do I really have to go to the stealership for a quality product?
 
I've heard iffy things about the aftermarket multi-function switches, so if in doubt, I would always use a Mopar replacement unless there is no other option.

However, it sounds like you may have a wiring issue somewhere that you're going to have to trace. Given the things the previous owner did to the vehicle, it stands to reason there may be some crappy wiring in there somewhere.
 
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Yea, I wondered about the wiring. But other than the fog light wiring being wadded up under the radiator, I haven't found anything wrong.
And the fact that out of 3 different multifunction switches, I have experienced 3 different problems..... doesn't sound like wiring to me.
I may try a Napa part tomorrow. If that still doesn't work, I'll check with the dealer on Monday.
 
I replaced the multifunction switch last night on my 2003 rubicon. Wanted to have functioning fog lights. PO removed fog relay as well. All works fine but, now the speedometer reads 50 at 25 mph and 95 at 40 mph with the engine cutting out. Only had this for a few months but it definitely gives me an excuse to spend time in the garage. No clue what the speedo issue is. I’m of no help just looking for a fix as well
 
Make sure to pull the fuse in the distribution panel under the hood prior to installing the MFS. Be sure that the hazard light button is not in the on position or it'll blow that fuse every time when you put the fuse back in. I've been thru 3 Napa MFS's in 3 months. Don't bother. Get a Mopar unit.
 
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bobthetj03 said:
Make sure to pull the fuse in the distribution panel under the hood prior to installing the MFS. Be sure that the hazard light button is not in the on position or it'll blow that fuse every time when you put the fuse back in. I've been thru 3 Napa MFS's in 3 months. Don't bother. Get a Mopar unit.
Click to expand...

Which fuse did you pull? Do you recall what it was labeled? I just got my switch and remembered your statement here.
Thanks
 
I replaced one in my father-in-law's 05 wrangler last year and it has been fine. I just don't remember where we got it from. I want to say Advance Auto, but not positive.
 
billiebob said:
Can't do that, Jeep is no longer making it and there is no stock left in North America .... ask me how I know.
We are stuck with the after market Assian products.

I think the Crown unit is $93.
Click to expand...
Interesting. The dealership offered to sell me a MF switch. Cost was like $189 & there was a no return policy. I wonder what it was they are selling?

As I mentioned above, I chose to pick up a Crown unit from Quadratec..... $87 shipped. It worked out great.
 
I got the Crown also....works great...did not pull any fuse and when I plugged it in , the flashers were on...……….just turned 'em off. No problems. Got from Quadratec.
 
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