go check the condition of your headlight switch and every plug associated with the blower motor RIGHT NOW.

[Pete M]

I've seen a shocking amount of melted plugs associated with the blower lately (including the plug behind the dash switches) and yesterday I went to grab a spare headlight switch from a rust free southern Jeep in the junkyard and found this:

 

 

 

 

and then I went to another Jeep and found the same thing.   the headlight relay harness is a good start, but the entire hi-amp system needs to be checked out asap.  

[MiNi Beast]

well I'm glad you brought this up... i have had switch melt while also running a cheap window defroster plug in to dash lighter. bad ordeal but new switch and no more cheap gadgets. 

 

however after taking out a sealed beam this weekend in the woods, i need more tube, but i want to rerun all new lights and blinker harnesses. full truck. and was wondering about replace this switch to eliminate this issue(s), and furthermore install any style headbeams. 

thoughts?  

[Pete M]

do you have the relay harness for the headlights yet?

[MiNi Beast]

i have 92 xj wiring dash and all

[MiNi Beast]

all stock yet yes  

[eaglescout526]

I checked mine really recently. The only melted plug I ever found was my blower motor switch plug and that was replaced when I added AC. And I don't drive much at night so headlights are rarely used except in the winter on my way to work and that plug was still in perfect shape. 

[Pete M]

the link is in my sig.  costs 15 bucks and takes a couple minutes to install. 

[MiNi Beast]

Just now, Pete M said:

the link is in my sig.  costs 15 bucks and takes a couple minutes to install. 

does it come with a sticker? 

[Pete M]

I mean, if you spend more cash at a big name store that gives out stickers, than yes.  

[eaglescout526]

I like that idea. A simple sticker that says "This Jeep MJ or XJ is equipped with the headlamp relay harness upgrade"

[Pete M]

"and will probably not burn down, or at least the fire most likely won't start in that location" 

[MiNi Beast]

i need the extra ponies though.  need a sticker. 

[jdog]

I believe i got one when i ordered one from k suspension

[eaglescout526]

Sticker will have to look professional in Helvetica font with the Chrysler corp and Pentastar logo on it or for us earlier and obsessed guys, the AMC|Jeep corp and logo on it. 

 

Shame I have no way of making such sticker.

[Pete M]

36 minutes ago, eaglescout526 said:

Sticker will have to look professional in Helvetica font with the Chrysler corp and Pentastar logo on it or for us earlier and obsessed guys, the AMC|Jeep corp and logo on it. 

 

Shame I have no way of making such sticker.

 

you'd be surprised what you can do with MS Paint and a little bit of help from your computer savvy friends to make it print-worthy   

[eaglescout526]

 

 

Pete, what have you done? Lol.

[MiNi Beast]

I'm in if get sticker. 

[cruiser54]

10 hours ago, MiNi Beast said:

i have 92 xj wiring dash and all

You're not exempt from these issues.

The headlamp harness is an absolute necessity and your headlights will shine about 35% brighter. 

 

90 and earlier can also benefit from improving the blower motor ground to address the issue of melted plugs under the dash.

 

See below:

 

CRUISER'S MOSTLY RENIX TIPS

HEADLIGHT HARNESS UPGRADE

NOVEMBER 17, 2015 SALAD 58 COMMENTS EDIT

It’s easy to install a supplemental headlight harness.

From the factory, the voltage to the headlight bulbs travels from the battery, through connectors, inside the cabin, to the headlamp switch, and then back out to the lamps via undersized wire and more connectors. It’s not uncommon to find only 10.5 volts at the lamps.

The supplemental harness is installed so that it provides battery voltage to the lamps and is just triggered by the factory wiring. The result is about 35% brighter headlamps and headlight switches that don’t melt and burn out.

Here’s a link to a harness on ebay: http://www.ebay.com/itm/CERAMIC-H4-HEADLIGHT-RELAY-WIRING-HARNESS-2-HEADLAMP-LIGHT-BULB-SOCKET-PLUGS-7-/330997592807

Absolutely plug and play:

• Remove grille and headlamp bulbs. I fed my harnesses from the passenger side starting between the battery and the back of the headlamp housing, over to the driver side.
• Plug the driver side bulb into the new harness.
• Attach the new harness’s ground wire under one of the small bolts on the radiator support after scraping the paint off under it.
• Attach the harness to the existing harness behind the grille working toward the passenger side.
• Plug the new harness plug into passenger headlamp.
• Plug original headlamp plug into receptacle on new harness.
• Attach the ground for the passenger side just like you did the driver side under a radiator support bolt.
• Attach relays with provided bracket on the passenger side inner fender.
• Connect power wires to battery.

CRUISER'S MOSTLY RENIX TIPS

IMPROVING BLOWER MOTOR PERFORMANCE

NOVEMBER 28, 2015 CRUISER54 24 COMMENTS EDIT

On 1984 to 1990 MJs and XJs, the blower motor’s factory grounding point is on the driver side inner fender under the sheet metal screw. This ground is shared with windshield wipers, front windshield washers, rear windshield washers, AC clutch relay, fan control relay, fog lamps, fan motor, headlamps, front turn signals, front side markers, and park lamps.

So your blower motor has its ground point 10 feet away from where it is located!!

What we’re going to do is leave that ground intact and also ground the blower motor on the passenger side inner fender much closer to the blower motor itself. This will also benefit the other components on the factory ground circuit. Take this opportunity to refresh the factory ground as a matter of course. Remove the screw, scrape the surface to bare metal and reinstall the screw securely.

Here’s what I do to get the ground much closer to the blower motor and add another ground point to this overloaded ground circuit.

Find the blower motor connector on the passenger side. Red and Black two wire connector.

Find a location where the black wire can be made to reach the passenger side inner fender, and cut the wire. You may have to do some rerouting of the harness to achieve this.

Take both cut pieces of wire and put them together into a yellow eyelet and crimp. Fasten the eyelet to a place on the passenger side inner fender with a sheet metal screw after applying OxGard to the contact surfaces. Be sure to scrape the attaching point on the fender to bare metal first.

Your blower motor will now turn faster and last longer, and the other electrical components on the circuit will benefit from a better ground path. 

[Andy in Pa]

I was going to build my own circuit for this, but doing it this way would be WAAYY easier.  I clicked on that link though, and it looks like the one linked up is not compatible??  Am I missing something?

 

[cruiser54]

Might as well do this also. very worthwhile.

Keep in mind Tips 1 through 5 are absolutely necessary to do.

 

CRUISER'S MOSTLY RENIX TIPS

IMPROVING THE INSTRUMENT PANEL GROUND

NOVEMBER 17, 2015 SALAD 14 COMMENTS EDIT

 

The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼” or 5/16″ head on it.

This ground point is responsible for handling the ground circuit for the following items: Dome lamps, seat belt and key warnings, transmission power/comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.

The problem is that where the ground point is located does not share good contact with the chassis where the ground should be. The solution is simple:

• Make up a jumper wire with #10 gauge wire about 10″ long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8″ round wire terminal.
•  
• Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
•  
• Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely. Use a coating of OxGard at all ground contact surfaces when attaching the screw and nut.

**Special note for Comanche owners: Make your jumper wire 12″ long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**

[cruiser54]

Just now, Andy in Pa said:

I was going to build my own circuit for this, but doing it this way would be WAAYY easier.  I clicked on that link though, and it looks like the one linked up is not compatible??  Am I missing something?

 

It's compatible. No worries. 

[Andy in Pa]

8 minutes ago, cruiser54 said:

It's compatible. No worries. 

Ok, thanks!!

[Pete M]

5 minutes ago, Andy in Pa said:

Ok, thanks!!

 

if you're referring to the ebay link, ebay encourages the venders choose the models the part goes with, but there's a cap on the number that ebay lets yous choose so sellers make multiple listings so that when someone searches for their particular car, it'll pop up.  and this harness goes to a LOT of vehicles.  anything that came with the h4 headlight plugs is cross compatible.  

[Andy in Pa]

2 minutes ago, Andy in Pa said:

Ok, thanks!!

I have done the other two ground wiring mods, and have the relays around here (from other projects) to do this headlight circuit.  Have the circuit drawn and everything, just didn't have time to build it.  Just ordered this instead.  Can't build it for that price.  That is actually more affordable than building it myself.  Thanks for the reminder!!