How To Make All 4 Headlights Illuminate With Wagoneer Header

[joester1908]

 

Ok so if you own an XJ Wagoneer, or have an XJ Wagoneer grill on your XJ or MJ like I do, you probably know that the top 2 lights are your low beams, and the bottom 2 are your high beams. This will tell you how to make only the top 2 low beams come on with low beams, but all 4 come on with high beams.

 

Low Beams:

Factory High Beams:

After the Swap's High Beams:

You will need:

-3 relays

-14 gauge wire (I recommend black, red, white, and green, to match the factory wiring)

-Spade connectors 

-Wire crimpers

-Wire strippers 

 

Here is a wiring diagram that my dad drew up:

Start by locating your headlight harness wiring. You have a black plug under the air box on the drivers side. You will need to uninstall this to access the plug. While you are accessing the plug, Cruiser recommends using an electronics cleaner inside. It likes to get green inside, which causes resistance. You can find more information on his Renix Tips Thread

 

Now you need to decide where you want to mount your 3 relays. I mounted mine where the core support bolts to, I don't have the factory air box. There is also room on the drivers side inner fender. 

 

Next, you need to decide where you want to splice in to your headlight harness wiring. I did mine on the header panel side of the plug. The only downfall to this is if you uninstall your header panel, you will need to unplug the relays. The upside is that you have more to work with. 

 

Here are the relays and their diagrams

Ok, on to the wiring:

Your low beams are controlled by a solid green wire. There is also a green wire with a black stripe. I believe this goes to your factory fog lights, but I'm not sure on that. Your high beams are controlled by a solid white wire. 

 

This part is the exact same as a normal headlight relay swap. You are going to make 2 separate systems. 

 

1- Cut the green wire so you have plenty to work with on both sides. If you're standing at the driver's tire, to your left will be the header panel, and your right will be the cab of the Jeep. The left side will be to the lights, the right side will be from the switch. You will need to extend both these wires so they are long enough to reach your relays. The switch side of the green wire will go to either 85 or 86 on the relay. The other goes to ground. It does not matter which you choose. 

2- You need 12v from the battery that goes on 87. I would run 2 separate 14 gauge wires (In red) that are both fused. 

3- Now hook the headlight side of the green wire to 30 on the relay. 

4- In the spade connector on 3 of the low beam relay (green) you are going to make a jumper to the 3rd relay. You are going to add another piece of green wire that is about 4-6 inches long, and add a spade connector on the end of that. So the headlight side of the green wire will have 2 spade connectors on it. Once you have completed this, leave it, we will come back to it later.

 

Now you will do something similar for the white wire:

 

5- Cut the white wire so you have plenty to work with on both sides. If you're standing at the driver's tire, to your left will be the header panel, and your right will be the cab of the Jeep. The left side will be to the lights, the right side will be from the switch. You will need to extend both these wires so they are long enough to reach your relays. The switch side of the white wire will go to either 85 or 86 on the relay. The other goes to ground. It does not matter which you choose. 

6- Now you will hook the other red 14 gauge wire that you ran to the 87 on your relay. 

7- Now hook the headlight side of the white wire to 30 on the relay. You will need to make 2 jumpers out of white wire, just as you did with the green wire. The white wire will have 3 spade connectors, all 4-6 inches apart from each other. If you follow the wire at this point, it will come from the headlights, to 30 on your relay, then 2 more spade connectors. I hope that made sense. 

 

Now you will wire your 3rd relay:

 

8- Hook either 85 or 86 to ground, again, it doesn't matter which you choose, but I would do the same on all 3 for consistency. 

9- Connect one of the spades on the white wire jumper (Which comes from 30 on the high beam relay) To 85 or 86 on the 3rd relay (Whatever you didn't pick for ground)

10- Connect the remaining white jumper to 87 on the 3rd relay.

11- Use the green jumper you made in step 4 (Coming from 30 on the low beam relay) and connect it to 30 on your 3rd relay.

 

And here is what my relays look like all mounted: 

I hope this makes sense to you guys. I know the wiring is a little messy, but pretty much the low beam relay is only going to power the low beams, and the high beam relay will power both the high beams and the low beams.

 

I understand this could be done with a diode, but it would need to be 20 amp, which I could not find. I had relays lying around, so why not. 

 

 

[Dillithium]

That's some clever stuff! How's the light output now?

[hick92]

 

 

Maybe this will help make it a little easier if you can find it in 14awg

[mikekaz1]

Curious. I'm having trouble following how you wired the third "x?" Relay...

Are you series wiring the 87 high output through the X coil then to the high beams and using the x relay to then switch lows?

 

An alternative would be a DPDT high relay and send one NO leg to high and one NO leg to low. (If in not mistaken) that would make low be only low with no high back feed. But control both high/low with high.

[Crash]

Nice job. Although an aftermarket/DIY upgraded headlight harness with this mod would make more sense. As these vehicles aren't best known for their wiring and possible headlight issues as it is.