AutobotXJ

Have a 92, 4.0 xj that has been giving me headligt troubles. I've gone through 3 switches in 2 months. The first time, it stopped turning on, second time it flickered, third time it initially turned on then off. I checked all my fuses initially, but didn't find any blown ones so i assumed it was a bad switch. By he third time, i scrutinized every wire and fuse and found a blown fuze that still looked connected. I fixed that and checked the wiring harness. Two of the contacts are melted. My question is this, 1) can a bad fuse cause excessive heat to melt the harness (shouldn't it stop current from getting to the switch?) and 2) can i safely bypass the harness to the switch using female spade connectors?
Thanks in advance,
Ray

XJ Stryker

I think you are on the right track. You got a short to ground somewhere. Once you put the new fuse it you allowed current and metled contacts.

I would use a smaller amp fuse so it will blow before melting contacts until you find out where your short is. you are really gonna have to just check all wiring for bare spots.

AutobotXJ

Thanks, i found loose connections on the harness under the airbox and so i deleted the harness from the equation and directly connected the wires to each other. I want to do the same with my headlight switch. Do you think it's safe to do? The female spades i'll use will be insulated.

freegdr

if your headlight switch connector is melted a new one should be spliced into the harnes to the old one, spade connectors would be a last resort but they do work .loose connections will get hot causing melting issues

freegdr

http://www.airtexproducts.com/produc...g.aspx#...part no1p1190

cruiser54

The connectors being partially cooked can in and of themselves cause headlight switch failure.

AutobotXJ

Thanks everyone. I'm checking the junkyards for a new harness- i was able to return my headlight switch and get a new one. I can't believe the harness costs 60$ at Napa but that might be my only choice.
Ray

cruiser54

Replace the plug/connectors from the JY and solder it in. Then, get this upgrade harness to insure you don't have this problem again. The added bonus is that your headlights will be about 30% brighter. Easy to install. If you need a write-up for installation, I have it. Let me know.

http://www.eautoworks.com/Putco-H4--...s-PRD7540.aspx

AutobotXJ

Thanks for the link, i was going to build my own upgrade harness or this reason, but that link looks cheaper than what i can build (everything is more expensive in Hawaii). I couldn't find a switch harness at the JY so i am going to link it directly with spades until i find a replacement. It's my daily driver and need to take my young children to daycare and preschool.

freegdr

60.00 is a lot cheaper than a new xj after the fire...

NoClearCoat

X300 on what Cruiser and Freegdr said. I knew a guy who'd replaced his switch on his 73ish camero and left the toasted socket in, was on his way home from work a week later and he started smelling wire smoke, he got it stopped and snatched the batt cable off but by that time it had melted part of the panel on the dash and melted most of the harness under the dash. It was a big mess and a pain in the @$$ to piece it all back together. He was real lucky he didn't loose the whole car. That's why I carry a good ABC extinguisher beside my seat..

AutobotXJ

Don't worry, it was never a question for me not to replace the wires. My question really was whether or not it was safe for me to bypass the harness. It seems like it would be okay, but to be safe, i will replace it as soon as possible. I have no idea how long the wires have been faulty- years i think because after i repaired it, my voltage looks a lot more regular than the past 5 years! I also keep my extinguisher close by for that reason.

scottmphoto

My last XJ (a '92) had this problem. It fried the headlight switch shortly after I replaced the stock headlights with the Silver Star ones. The last time, it melted the connector and I definitely smelled melted plastic and the head lights died. I think it was just from the extra power that was running through the wiring (it wasn't made to handle the extra current over stock) and when I replace the headlights on my current XJ, I'm running them off of relays so just a minimal amount of power goes through the headlight switch and wiring.

Radi

Sure. I build new harnesses for vintage cars when necessary, replacements just don't exist. There's nothing magic about a wiring harness, just make sure to use the same or larger wire gauge (unless it's a fusible link- then use the same gauge) and insulated spade terminals on the back of the switch, not the bare metal ones. If they come off and contact the chassis, no harm done that way.
I don't trust crimp connections either, I normally add a bit of solder to the spade connector, then slide the insulator back into place.

Jeepman42

I have same problem.just found the connector pigtail at O'Reillys for 40 bucks (ouch!) Haven't tried it yet,but it is 9 pin part # BWD PT351 a new 40 amp headlight to headlight wiring harness with relay is available on eBay for less than 19 bucks.relay connects directly to the battery and uses the headlight switch to simply switch on the relay,thereby preventing future heat overload.