Should the multifunction switch harness look like this?

LJDC

TJ Enthusiast
Supporting Member
Joined
Feb 20, 2023
Messages
241
Location
D.C.
I finally got around to replacing the multifunction switch. My fog lights were on permanently, and I had to pull the relay until I replaced the switch. But it was cold, and I had other stuff to do; so I procrastinated until today. Anyway, it’s now fixed, and the fog lights work correctly.

But when I pulled the main harness (the big one on top), it looked like this. Does it look a little, I don’t know, melted?

IMG_6237.jpeg
 
My son's connector looked like that. I replaced it . Something was hot at one time but it seems to be fine now. After I replaced it, its been fine.
 
  • Like
Reactions: LJDC
I finally got around to replacing the multifunction switch. My fog lights were on permanently, and I had to pull the relay until I replaced the switch. But it was cold, and I had other stuff to do; so I procrastinated until today. Anyway, it’s now fixed, and the fog lights work correctly.

But when I pulled the main harness (the big one on top), it looked like this. Does it look a little, I don’t know, melted?

View attachment 515267

I'd replace it. Pigtail is $50 on RockAuto.
 
  • Like
Reactions: Fulton_Hogan
That’s really helpful. Thank you.

Does anyone think the bad multifunction switch could be what caused the melting? I had suspected that it was causing a slow drain in the battery, even with the relay for the fog lights pulled.

You got it! That's why this place exists.

To my understanding, the melting occurs due to how the vehicle is wired.

The current is always on to the left side of the connection and the switch.

Over the years it eventually becomes too much for the plastic, it melts and you are where you are.

Running stronger than stock headlights can also contribute to the overheating and eventual plastic breakdown. (I believe it was @Jerry Bransford who stated this.)

There a few members here who have rewired a portion of their harnesses to eliminate the chance of it occurring again. I can't find those posts at the moment, but their notes are in here. Somewhere.
 
  • Like
Reactions: Andy-WhiteTJ
Where does it lead? Meaning, am I replacing just the plug and reattaching every wire?

Have you ever done a radio? You would terminate the wires just before the bad connector and reattach them to the new connector (that has wires coming out of it) with crimp connectors. You would have a harness wire to new wire spliced pigtail. You wouldn’t be making a connector, if that’s what you mean.

In other words, it’s easy and WAY worth the effort. Just don't use wire nuts. Those don't hold up to vibration. Pull test every connection too.
 
Last edited:
Have you ever done a radio? You would terminate the wires just before the bad connector and reattach them to the new connector (that has wires coming out of it) with crimp connectors. You would have a harness wire to new wire spliced pigtail. You wouldn’t be making a connector, if that’s what you mean.

In other words, it’s easy and WAY worth the effort. Just don't use wire nuts. Those don't hold up to vibration. Pull test every connection too.

Actually, my son's was much easier. Since the old connector was quite brittle from the heat, I was able to break it apart and reuse all the wires and metal pins intact. I just kept the order of wires the same and the metal pins on each wire just clicked into the new connector.
 
  • Like
Reactions: Fulton_Hogan
Actually, my son's was much easier. Since the old connector was quite brittle from the heat, I was able to break it apart and reuse all the wires and metal pins intact. I just kept the order of wires the same and the metal pins on each wire just clicked into the new connector.

mood GIF
 
  • Like
Reactions: astjp2
Have you ever done a radio? You would terminate the wires just before the bad connector and reattach them to the new connector (that has wires coming out of it) with crimp connectors. You would have a harness wire to new wire spliced pigtail. You wouldn’t be making a connector, if that’s what you mean.

In other words, it’s easy and WAY worth the effort. Just don't use wire nuts. Those don't hold up to vibration. Pull test every connection too.

I’ve done many radios, but 20 butt connectors seems bulky and not ideal. The idea below sounds great, but my connector doesn’t seem quite as brittle, so breaking it apart might be too destructive.

Maybe I’ll order the conductor and see how it looks. Thanks!
 
The black face of that harness connector pops off easily, it's held on by a tab on each side.

Once you have it off, based on your picture, it'll be very easy to wiggle the wire pins out of their housing and into a new one.

I think you'll be surprised at how quickly the original crumbles once you get going.