Headlight wiring harness upgrade

After reading several posts about upgrading the headlight wiring I decided to upgrade the headlight wiring harness on my ’99 XJ. What a difference it has made!! The increase in light output seems to be as much of a difference as switching from the stock sealed beam headlights to Cibie 200mm (H4 bulbs) but the Cibie have a much better beam pattern. Of course this took about 3 times as long as I thought it would have but was well worth the time and effort!

:thumbup:

wcbuyer said:

After reading several posts about upgrading the headlight wiring I decided to upgrade the headlight wiring harness on my ’99 XJ. What a difference it has made!! The increase in light output seems to be as much of a difference as switching from the stock sealed beam headlights to Cibie 200mm (H4 bulbs) but the Cibie have a much better beam pattern. Of course this took about 3 times as long as I thought it would have but was well worth the time and effort!

Click to expand...

Oh man you are right. I found an "APC" ricer H4 upgrade harness on EBaY for like 15.00 i think. That made it much easier and cheaper than the parts i would have purchased to make it...
I had a diagram made up and everything.....That harness came with relays and everything.....
No matter how you go....its a good thing to do...

I thought about buying a harness but I could not find out what gauge the wire was. I did not want to do a harness with 18 gauge wire. I used 14 for mine.

Can you post a link to this upgrade please.

Thanks,

Ken

http://www.go.jeep-xj.info/HowtoHeadlightLoom.htm

Definitely use 10 guage wiring.

This is a great write-up!

I have an '89 MJ and want to do the same upgrade. I couldn't figure out how the headlight switch on the dash controls this new wiring configuration.

Can anyone explain how this new wiring 'taps into' the switch?

You plug the trigger wires for the relays into the stock harness. This is exactly how I'd like to do mine- nice and tidy and overengineered.

http://fitchva.com/jeep/?p=57

Is there an icon for waving the white flag of surrender?

I've consulted both write-ups in this thread and I followed the Canadian version because the relay ground needs to go to the 85 pin.

Both write-ups are similar in how the high & low beam wires are connected to the relays. However, here are my problems when all the wires are connected:

1. With light switch off, one low beam headlight is on.

2. With headlight switch on, both low beams come on.

3. With high beam switch engaged (pull the turn signal stalk), no lights at all.

I've mixed and matched the high & low beam wires between the relay pins and I can get the highbeams to go on individually or at the same time, but I can't wire it up so everything works as it should.

Can anyone offer a clue as to what might be wrong here? I have an '89 MJ without fog lights.

I'm confused. Did you do one relay for high beams and one for low beams? Is this all confused by having daytime running lights, which I think put the headlights in series for the daytime mode?

Sounds like you have a couple of wires switched around. I would go back and double check the wiring layout that you used to make sure it's setup exactly like go-jeep and fitch have it designed. Being an 89 with no fogs means there's also no drl so that's not going to cause a problem. You should have both factory connectors unplugged, one of them providing the power signals for the high and low beams to both relays. Two relays one high other low beam, signal from stock connector to pin 86 ground on 85 power from batt. on 30 and 87/87A from each relay going to either high or low beam connector.

Try this. This is the diagram that i used. It uses 85 as the ground The power wire can come right from the batt, it doesn't have to come from the alt. like in the pic