Headlight Wiring Harness Questions

[91Pioneer]

Hey gogmorgo (or others) do you have a pic of the relays mounted under the hood?

 

I clipped off some headlight socket plugs last time I was at the junkyard (free), I figured OEM plugs are better than almost any aftermarket stuff. And I already have regular relays, some wire, and every crimp connector I need and then some. So it's basically a free upgrade and won't be screaming yellow when done LOL.

 

Oddly enough I actually enjoy wiring (not necessarily finding faults in wires though) :)

[gogmorgo]

Here's the how-to I followed, but I don't have a pic of my own work. I never got around to properly mounting them somewhere, I just left them tucked down beside the battery. I also don't have the Putco harness, so mine was all red, green, and black, but I just tucked it into some split loom (cheapish at Princess Auto) so it wasn't obvious.

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

 

Editing to correct a broken link: http://gojeep.willyshotrod.com/HowtoHeadlightLoom.htm

Edited May 28, 2023 by gogmorgo

[cruiser54]

Here's an interesting link on LED headlights:

 

http://www.cherokeeforum.com/f59/truck-lite-led-pros-cons-review-pic-heavy-202918/

[ParadiseMJ]

So, I gotta ask...in gogmorgo's wiring diagram I don't see where anything goes to the switch...what am I missing??

[gogmorgo]

Correct. There is nothing going to the switch.

 

The supplemental harness plugs into one of the factory headlight sockets (which I guess is going to the switch...) and uses the complete factory headlight wiring to trigger the relays. Basically, where the bulb(s) used to be in the factory circuit, there are now relays.

 

Beyond unplugging the headlight bulbs from their sockets and plugging some trigger wires into one side, you do not need to modify the factory wiring at all.

[cruiser54]

Correct. There is nothing going to the switch.

 

The supplemental harness plugs into one of the factory headlight sockets (which I guess is going to the switch...) and uses the complete factory headlight wiring to trigger the relays. Basically, where the bulb(s) used to be in the factory circuit, there are now relays.

 

Beyond unplugging the headlight bulbs from their sockets and plugging some trigger wires into one side, you do not need to modify the factory wiring at all.

Yup.

 

Cruiser’s Headlight Upgrade Harness Instructions

 

 

It's easy to install a supplemental headlight harness.

 

From the factory, the voltage to the headlight bulbs travels from the battery, inside the cabin, to the headlamp switch, and then back out to the lamps via undersized wire. 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 30% brighter headlamps and headlight switches that don't melt and burn out. 

 

 

 

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. 

 

Revised 12/10/2012

[87MJTIM]

It's "eazy-peezy-lemon-squeezy."  Took me 1 hr.  I also installed HE lights.

[88mjblue]

Here's the how-to I followed, but I don't have a pic of my own work. I never got around to properly mounting them somewhere, I just left them tucked down beside the battery. I also don't have the Putco harness, so mine was all red, green, and black, but I just tucked it into some split loom (cheapish at Princess Auto) so it wasn't obvious.

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

 

Is there another headlamp supplemental harness upgrade that someone makes? I ask because amazon is sold out of the Putco harness, and some people have said the Putco is poor quality. Yet, others say it is fine and people just have grounding and mounting issues...

[HOrnbrod]

http://www.speedwaymotors.com/Headlight-Relay-Harness-Kit,58825.html

 

Many more - search for "universal headlight relay harness".

[gogmorgo]

Specifically you're looking for an H4 harness.

 

If you're a bit savvy with wiring, you could also make your own.

 

Edit: and here's the wiring diagram I made earlier in this thread and TOTALLY FORGOT ABOUT. LOL.

 

Another edit to correct the now-broken link above:

http://gojeep.willyshotrod.com/HowtoHeadlightLoom.htm

 

[HOrnbrod]

Specifically, most sealed beam, halogen or H4 headlamp relay harnesses will work just fine. Or you can fab your own too. Easy peazy.

[gogmorgo]

:yeah that:

[88AKChief]

Here's an interesting link on LED headlights:

 

http://www.cherokeeforum.com/f59/truck-lite-led-pros-cons-review-pic-heavy-202918/

Surprised that these lights are DOT approved considering- thats a huge concern up here when the snow really comes down.

[cruiser54]

LMC truck sells the same harness.

 

And, there's this:

 

http://www.ebay.com/itm/H4-H4-HEADLIGHT-BLACK-BOOSTER-WIRE-HARNESS-K0TG-/201205671223?hash=item2ed8cae537&vxp=mtr

[NickyV]

I am late to this thread and others about headlight harness upgrades. I made a lot of progress last night building my own upgrade. I stopped because it was late and because I want to do this right.

 

I’m following @gogmorgo’s diagram, and I’m trying to do it with minimal splicing and grounds going all the way back to the negative terminal on the battery (or more specifically to a terminal block connected directly to the negative terminal).

 

Some questions I have:

 

1) What do people recommend for the new headlight plugs? Direct links or part numbers + brands are helpful.

 

2) What do people recommend for the relays? Same request with links/part numbers/brands.

 

3) I already have two crimp-on terminal connectors bolted to the positive terminal of my battery and I think it is time to upgrade to a more elegant solution. I’m hoping for a terminal bank with ports. I picked one up at AutoZone last night but didn’t read the package closely. Each terminal is a max of 20 amps. That seems like it won’t do. Anyone have a positive side terminal bank that they like?

 

Thanks!

[schardein]

For the headlight connector, go on Rockauto and search for Standard Motor Products HP3950 ($1.97).  Relay, Standard Motor Products RY116 ($5.10).  Although you might search around and find a relay with a mounting tab.  That might be useful depending on how you make your harness and where/how you intend to mount your relays.  Although you could just tape them to the harness. 

 

As for a terminal block, lots of ways to go.  One thing to keep in mind, Amps x Volts = Watts.  So if you have a 20 amp circuit, multiply that by 12 volts, that's 240watts!  Another example, a light rated at 100 watts, divide by 12, equals a draw of 8.3 amps.  A 20 amp rated circuit is enough to handle a pair of most halogen headlights, which are commonly rated at 35 watts low beam and 65 watts high beam.

 

 

[NickyV]

Thanks @schardein. I'm attaching a pic of the fuse terminal I picked up the other day, which I was thinking about returning. It has six terminals. I was thinking that I could use it for a handful of the additional accessories I'm running off my battery, but then I saw 20 amp max and it seemed like people here were recommending 30 amp relays, so I thought this didn't have the capabilities I needed. Maybe I'm wrong about that. (Edit: I would not be surprised in the least if I'm wrong about that.)

 

 

In addition to the fuse terminal, I'm also going to attach the pics of the harness I've put together. I'm glad to see that some people are saying they paid close to $100 for a high quality one, because that's about what I spent on all the components, and I don't even want to talk about the labor I put into this. Lol. The pictures of the harness have everything except the fuses, which need to go somewhere along the two shorter red cables with the ring tips. I know I can also do inline fuses. I need to go back through this thread and read what some have said about what the fuse should be, but if someone cares to tell me here, that'd be great too!