Replaced multifunction switch for fog light fix, now interior dimmer doesn't work

[Echo5]

I bought a new Mopar multifunction switch and replaced the old one my 2002 TJ Sahara. After the swap I found my fog light relay was removed by the previous owner so I need to get one of those. Stupidly I buttoned everything back up without testing the interior dimmer and it doesn't work. I had checked everything else - headlights, high beam, turn signals, emergency blinker, windshield wiper & washer.

Before I rip out the replacement unit is there anything I may have missed? Is it possible that the new unit is DOA for the interior dimmer function?

The interior lights illuminate when I open either door and function normally in all aspects otherwise.

 

[Chris]

Does the new switch turn on and off the dome lights but just not dim them, or does it just not work at all in regards to the dome light?

 

[Echo5]

Does the new switch turn on and off the dome lights but just not dim them, or does it just not work at all in regards to the dome light?

No function at all. Sorry, I forgot to put that in my initial post.

 

[Chris]

Sounds like that switch could be DOA. As long as you plugged everything back in, there's no reason it shouldn't work. I replaced mine due to the fog light issue, and the new one went right in without any issues at all.

 

[Echo5]

Thanks! I figured as much about it being DOA, just wanted to make sure I hadn't missed something dumb. I'll swap the old unit back in later today and update the thread for future reference.

 

[Chris]

Thanks! I figured as much about it being DOA, just wanted to make sure I hadn't missed something dumb. I'll swap the old unit back in later today and update the thread for future reference.

No problem. I think that must be your issue. I've taken apart these multi-function switches to repair them before, and once you see the inside of them you'll completely understand why they fail.

Speaking of which, it's easy to repair your old one if you want. Follow this thread (as I did when I repaired mine):

How to repair multifunction switch for fog lights (fog lights that won't turn off)
How to fix flickering fog lights or fog lights that won't turn off

 

[Echo5]

No problem. I think that must be your issue. I've taken apart these multi-function switches to repair them before, and once you see the inside of them you'll completely understand why they fail.

Speaking of which, it's easy to repair your old one if you want. Follow this thread (as I did when I repaired mine):

How to repair multifunction switch for fog lights (fog lights that won't turn off)
How to fix flickering fog lights or fog lights that won't turn off

My plan was to use the new OEM as the quick fix and then repair the old one as per the linked threads and swap out as they failed over time using the "one is none and two is one" rationale.

 

[Chris]

My plan was to use the new OEM as the quick fix and then repair the old one as per the linked threads and swap out as they failed over time using the "one is none and two is one" rationale.

Ha, I did the same thing on mine! Great minds think alike I guess!

 

[Echo5]

So I just swapped the new switch with the old one. Interior dimmer/dome function works again.

 

[Chris]

So I just swapped the new switch with the old one. Interior dimmer/dome function works again.

Sounds like they sold you a "new" switch that has something broken inside.

 

[Echo5]

Sounds like they sold you a "new" switch that has something broken inside.

Yep. Ordering another now.

 

[Echo5]

The replacement MFS worked like a charm. Just a reminder to check everything BEFORE you button it back up - I did this time!

 

[Chris]

The replacement MFS worked like a charm. Just a reminder to check everything BEFORE you button it back up - I did this time!

Thanks for the update, sounds about right to me too! I had to take my MFS apart 3 times before I got it back together and working correctly!

 

[Echo5]

Thanks for the update, sounds about right to me too! I had to take my MFS apart 3 times before I got it back together and working correctly!

I am now a master at aligning the top and bottom halves of the steering column housing! Watch out for pinching those tabs...

 

[Chris]

I am now a master at aligning the top and bottom halves of the steering column housing! Watch out for pinching those tabs...

Ha, I can relate 100%!