2005 LJ Rubicon - headlight switch/wiring overheating

[Jim K in PA]

Over the last few months I have noticed the the top column cover on my LJ gets hot when I use my headlights for extended periods of time. Recently I had the headlights and the OEM fog lights on for several hours, and the smell of hot plastic started to be noticeable. Has anyone else experienced this with their TJs/LJs?

It is my understanding (although I have not looked at the wiring diagrams) that the power for the headlights and fog lights actually passes through the cabin switch. If so, it seems that the current load is now exceeding what the wire gage is capable of handling safely. I have not burned any fuses, and the lights, wiring, connectors and even the bulbs are 100% original with 140k miles of use. I suspect that there is corrosion building up on the connectors that is adding resistance to the circuit.

Time to add some relays and appropriate gage wiring, I suspect.

Thanks for any input.

 

[Hilldweller]

I sure would. http://www.danielsternlighting.com/tech/relays/relays.html

Check for any shorts to ground too. I can't imagine them putting all that amperage through the switch though.

Maybe some lower aperage lights while you're at it too?
Looky here: http://www.candlepowerforums.com/vb...-Updating-7-quot-round-sealed-beam-headlights

 

[reece146]

This is likley a symptom of cheap ChryCo wiring.

My XJ did something similar... I tend to keep the dash lights dimmed to the lowest setting to help night vision. This makes the headlight switch portion that does the dimming (a rheostat) run hot and it causes the switch and/or wiring to melt... possibly causing a fire inside the vehicle.

Mine almost caught fire: melted, charred, black mess of a head light switch connector. Since you have a melted plastic smell I'll guess when you take the column apart you'll find something similar.

I ended up having to pigtail all the wires after they entered the cabin in order to hook up to the replacement headlight switch.

I'm guessing that the TJ being a similar vintage Jeep does the same thing.

I always intended to figure out a different way to do this but around this time the time the Jeep stopped begin a daily driver so I never got around to it since the need wasn't there.

Relays, heavier gauge wiring... that would be the approach to take like you suggest. IF there was a way to relocate the rheostat and/or replace it with something else that would be good too.

 

[hollaback55]

the switch handles all the light duties and takes the amperage. While taking our expedition across the US in the LJ towing the trailer, I had my headlight switch burn up and short out. I had to replace the switch with a new one from Autozone as well as a new wiring kit from mopar. Apparently the trailer put an additional load and cause the wires to melt. The switch is a poor design (well documented on jeep forums) and is inadequate in stock form. Once you wire up a 7 way for the trailer it expedited the process of melting/smoking/burning. We were heading north on Pacific Coast Highway 1 and my column started smoking. Lights went out 1/2 hour later. Thank god for my Baja Designs 10" Stealth or we would have been in deep ********.

Now how to fix it. Take apart the cover for the column and undo the headlight switch torx fasteners on top of the column. then wiggle the grey connectors out on the right hand side of the steering column (this is a separate switch for the wipers) and the large plug on the left hand side at the back of the switch. You can now remove the switch assembly and inspect the grey plug for the headlights, fogs, dimmers, ect as well as the plastic on the back of the switch itself.

On mine was that it actually melted the plastic, wires, and essentially soldered the wire ends to the plastic becoming a jumbled mess that had to be replaced. The new wiring kit from mopar has heavier duty wire (thicker gauge) to handle the load and comes with all the necessary hardware. I choose to solder and then shrink wrap all my connections instead of using their brass connectors but that is up to you. The wiring kit from Mopar was $70 if I remember correctly and the new switch from Autozone was $55 or so.

Its important to keep the wires labeled and to make a diagram or take pictures of which wires go where. Some of mine had melted so it was hard to discern where they were suppose to go. Also pay attention to which way the connector end goes into the blade on the switch. I mistakenly inserted some of mine upside down and it took me a week to figure that out. Had no hazards or turn signals until I finally got it fixed. If you have any questions just pm me and I can give you a more detailed explanation on why it burned up and how to replace it.

hope the pictures help.

 

[Jim K in PA]

Wow. Thanks guys. This is what I suspected. My LJ has just recently ended it's duties as a daily driver, and will be getting a number of things addressed as well as the next wave of modifications. A few comments:

Bill - thanks for the link, and I was already aware of your affinity for the JWS 8700. They are pretty damned fugly though . . . I have been considering the Trucklites (latest iteration), but I am probably going to stick to my original plan and get the Cibie H4s from Dan. He and I exchanged a long series of emails on the options. I am actually going to use the Cibie reflectors with different bulbs for my supplemental lighting.

Reece - that is an interesting point to consider on the panel light dimmer. However, I have never noticed the switch itself getting hot at the control end, just the upper column cover panel and the base of the stalk. I will look into the remote rheostat. The car I just rented had a remote panel dimmer control on the dash.

Holla - So that wiring kit from Mopar apparently addresses a known issue with the wiring overheating? Do you have a part number for that kit? That was lucky that you did not have a more serious problem on the road during your trip. This is exactly what I am trying to avoid.

An additional note: I have been in the habit of running my headlights all the time over the last 6 years. I am sure that has contributed to the breakdown of the poor wiring.

I also added the Mopar factory 7-wire trailer harness to my LJ, although I have only towed a trailer with it a handful of times. However, I am going to check the trailer harness for shorts or other issues, as it may be why the problem has gotten worse in the last couple of months.

Thanks again for the input.

 

[hollaback55]

part number is in the picture in the previous post. its at the top of the package starting with the number 1 and it is in bold type. the wiring kit is definitely thicker gauge so I surmised that mopar knew about this issue and made the replacements of a thicker gauge. running your headlights continually will cause the same issue.

 

[titleguy]

This happened she I was running HIDs and I had a relay setup. Not fun to fix. It's one of the reasons I went to trucklites because the draw is so much lower. I run without a relay and have no issues.

 

[Jim K in PA]

part number is in the picture in the previous post. its at the top of the package starting with the number 1 and it is in bold type. the wiring kit is definitely thicker gauge so I surmised that mopar knew about this issue and made the replacements of a thicker gauge. running your headlights continually will cause the same issue.

Doh! Didn't notice the Mopar logo when I looked at the pic the first time. I did search for that part # but nothing comes up in the online Mopar parts sources.

Is that just a bunch of wires, or is there a new connector block as well? If it is just wire, I may just eliminate the connector like you did and avoid another point of resistance in the wiring.

 

[Jim K in PA]

This happened she I was running HIDs and I had a relay setup. Not fun to fix. It's one of the reasons I went to trucklites because the draw is so much lower. I run without a relay and have no issues.

If I convert the switched circuit to a dry contact from a load contact, then I eliminate all the power load from the column harness and switch. The LEDs do have less load, but I would rather move the load to where it belongs - on heavy gauge wire under the hood.

I am not sure if I am going to make up my own or get a DS or Rallylights harness.

 

[Jim K in PA]

Just took it apart and found the same thing.

 

[Jim K in PA]

The part # for the replacement connector kit is 05183442AA for the 2005 and other Jeep TJ/LJ. It is also used to repair the same problem in other Chryco vehicles like the PT Cruiser.

A good summary is here: http://www.jeepforum.com/forum/f9/05-multifunction-switch-harness-melted-1071190/

I just ordered the repair kit here for about $60 with shipping: http://www.factorymoparparts.com/05183442aa.html

Rockauto has the replacement switch assembly for about $80 plus shipping.

Hope this helps others with the same problem.

 

[Jim K in PA]

Just to close the loop - I got the new Mopar connector and wires spliced in last weekend. There are two different gage wires in the kit: 18ga and 14 ga. These gages match the existing wire, and is not an upgrade from stock. There are 20 of each gage in the kit, which is due to it being used for a variety of Chrysler vehicles with this same issue. There are brass crimps (two different sizes for the different gage wire) that I used for the initial mechanical connection, and then I soldered the joint. Heat shrink tubing is also included in the kit. With the new switch unit, all works as it should. Total time was about two hours.

It is clear that this is an overheating issue, not an overcurrent problem. The wires were heat damaged for only about 10-20mm along the insulation, reflecting the heating of the blade connector, not the wire itself.

Next step is a conversion to power relays under the hood, and then lighting upgrades.

 

[Rubicon]

Just to weigh in here - similar, but not exactly the same issue. I've got a 2004 TJ Rubicon & when I changed out the headlights from factory to PIAA's, I ended up melting the connectors at the headlight bulbs. Was told - have no idea if it's true, but at least at the time the male connectors on the back of the PIAA bulbs were "thinner" than the OEM bulbs & therefore had just a bit of "slop" in the connection from the bulb to the wiring harness, causing a slight arcing that heated up the connectors & melted them.... I have no idea if this is still an issue, but have spoken with several TJ owners who had the same problem with the headlights I had.

Figured it out one night while driving home & I lost both headlights - luckily was close to home & there were streetlights!

I ended up changing out the headlight wiring loom in the engine & going with one of the Painless Wiring kits (don't have the part number) & haven't had a problem in the roughly 7 years since I made the switch. The wiring is much heavier gauge and the connectors seem more robust.

Finally, I haven't had the issue with the connections in the stack & I too tend to run my headlights day and night, and at night have the dash lights down pretty low for night vision.