The Multifunction Switch Blues

k0m0d067

TJ Enthusiast
Joined
Jun 9, 2019
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131
Location
Victoria Australia
Since before i bought my 03, it's had what I believe to be a MFS issue of some sort...the previous owner showed me how to jiggle and twist the ignition after starting, to get the blinkers and stereo to work...annoying at times, but tolerable...

Recently, the windshield wiper controls have been acting up...the interval wipers don't work (they just come on as non-interval wipers) the quick-wipe stops in the middle of the windshield unless you hold it down...the washers don't work reliably...etc...etc...

And now, my brake lights aren't working at all...gonna swap fuses and bulbs, to start with, but have heard the MFS can affect brake lights as well?

I saw a couple "How-to" write-ups for fixing fog-light issues with the MFS...anything similar for what I'm facing?
 
Last edited:
Sounds complicated. You got worn out parts best to replace with new rather than trying to repair.
 
First thing I would do is access the MFS and check the condition of the harness connections.
If the connectors and pin connections are in good condition; it is a common problem for the MFS to go bad.
Here are links to two online parts suppliers to purchase a new multi function switch.

Rock Auto
Geek Parts
 
I figured I would try fixing mine before buying a new one. Given, mine is a 99 and no fog lights and the issues were that it was rough and the hazards didn't come on some of the times I flipped the switch. But a of the functions technically worked, just not well.

I took it apart as carefully as possible and still had the springs pop out of their orientation. The multifunction switch was full of green oxidization. I cleaned it with isopropyl alcohol, put a super thin layer of white lithium grease on the contacts and attempted to reassemble it.

On the third try to reassemble, I put all of the components on the white side even though you would think assembling it from the black side is the right way. Went back together and is now working perfectly.

Saved $50 and learned something in the process.

Moral of my story - if you planning on replacing it, why not see if you can fix it first?
 
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I’m having a problem similar. Far some reason the terminals in the plug to the switch aren’t working. The lights come on when I touch the terminals together with wire but not when the switch is in. Everything works except the dash and tail lights. Any ideas?
 
I figured I would try fixing mine before buying a new one. Given, mine is a 99 and no fog lights and the issues were that it was rough and the hazards didn't come on some of the times I flipped the switch. But a of the functions technically worked, just not well.

I took it apart as carefully as possible and still had the springs pop out of their orientation. The multifunction switch was full of green oxidization. I cleaned it with isopropyl alcohol, put a super thin layer of white lithium grease on the contacts and attempted to reassemble it.

On the third try to reassemble, I put all of the components on the white side even though you would think assembling it from the black side is the right way. Went back together and is now working perfectly.

Saved $50 and learned something in the process.

Moral of my story - if you planning on replacing it, why not see if you can fix it first?

This is an old thread but I did attempt to repair my switch and did take it apart. As mentioned the parts will pop out. You do have to re-assemble most on the white side except 1 part that has a tight track to go into (at least this was my experience) and you have to hook it in. That said my issue changed slightly from blinker not always working to now blinker works but blinker lamp goes on (no blink) when not activated sometimes (and might be tied to depressing the brake).

I usually assume that a normal human can re assemble parts but this was pretty far on the how they heck do they do this side.

Overall - I'd highly suggest just replacing the part. The little allen heads strip easily too and I had to use some anti tamper triangular screw drivers to get them back in after stripping. Spent almost 3 hours (20 min taking it out and apart and 15 min cleaning and 2 hours at multiple attempts to get it assembled properly and functioning. I'll be ordering one next time I have another parts order.

Just some feedback for those thinking about it.
 
I figured I would try fixing mine before buying a new one. Given, mine is a 99 and no fog lights and the issues were that it was rough and the hazards didn't come on some of the times I flipped the switch. But a of the functions technically worked, just not well.

I took it apart as carefully as possible and still had the springs pop out of their orientation. The multifunction switch was full of green oxidization. I cleaned it with isopropyl alcohol, put a super thin layer of white lithium grease on the contacts and attempted to reassemble it.

On the third try to reassemble, I put all of the components on the white side even though you would think assembling it from the black side is the right way. Went back together and is now working perfectly.

Saved $50 and learned something in the process.

Moral of my story - if you planning on replacing it, why not see if you can fix it first?

When my instrument cluster lights and headlights starting having problems I disconnected the wiring harness(s), removed the MFS module and sprayed DeoxIT D5 electrical contact cleaner in the module and cycled the actuation arm and knob multiple times to clean the internal contacts. Waited several minutes to ensure the contact cleaner had evaporated and reinstalled the module. Both the instrument cluster lights and the headlight control worked properly again.

https://www.amazon.com/Hosa-D5S-6-DeoxIT-Contact-Cleaner/dp/B00006LVEU?tag=wranglerorg-20
 
This is an old thread but I did attempt to repair my switch and did take it apart. As mentioned the parts will pop out. You do have to re-assemble most on the white side except 1 part that has a tight track to go into (at least this was my experience) and you have to hook it in. That said my issue changed slightly from blinker not always working to now blinker works but blinker lamp goes on (no blink) when not activated sometimes (and might be tied to depressing the brake).

I usually assume that a normal human can re assemble parts but this was pretty far on the how they heck do they do this side.

Overall - I'd highly suggest just replacing the part. The little allen heads strip easily too and I had to use some anti tamper triangular screw drivers to get them back in after stripping. Spent almost 3 hours (20 min taking it out and apart and 15 min cleaning and 2 hours at multiple attempts to get it assembled properly and functioning. I'll be ordering one next time I have another parts order.

Just some feedback for those thinking about it.

Old thread but your timing is great. I had the same issue after reassembling. Periodically, the left blinker would come on solid. I thought it could be the brake but also could just be the springs are worn and the lever is sagging a bit - to the point where it makes contact.

I finally gave up and ordered an aftermarket one from Rock Auto. Just installed it about 6 weeks ago and it's working great.

I was worried about an aftermarket part but it's been fine. Was like $40 shipped.

Agree with your assessment 100%. Just replace it.