Headlight / Foglight wiring issues

Ever since I've owned this truck it had a Morimoto HID projector kit in it that was installed by the previous owner. I recently got in an accident and had to get a new passenger headlight. I was able to save the entire HID kit and will probably reinstall it in my new headlights sometime in the future. For now I'm just running LED's in my headlights. I removed the HID wiring harness, Morimoto MotoControl relay, and ballasts. When the HID kit was installed, it had low & high beam but I never got a high beam icon on the gauge cluster when they were on. I checked the bulb behind the cluster and it still just never worked (it never bothered me). But now with the HID kit removed and all the wiring for the lighting returned to factory, some strange things are happening. I still don't get a high beam icon on the gauge cluster, low beams work, high beams work only when you pull the lever toward you (flash), nothing happens when you push the lever toward the dash (lock high beams).
But when I activate the fog lights on the lever, that now controls my high beams. Fog lights will not come on, that function now locks on the high beams. When you remove the corner (turn signal lights), I can see that the fog light harness branches out from that harness and travels down to where the fog lights are. There is a bundle of 2 or 3 wires just taped up next to the plug that goes into my corner lights, surely that has something to do with it. That has always been there since I've owned the truck but everything worked fine with the HID system so I never messed with it. I'm curious if anybody has installed a similar HID kit on their first gen. There must be some kind of modification you have to make to the factory wiring to make all the functions work with the HID kit. I'm basically trying to revert it back to factory wiring so all the buttons in the cab control what they're supposed to control.

 

Topic is covered in the community megathread.

See the lighting section in the 1st reply. Make special note of resistors section.

This is a very well known and very well documented issue with dozens of similar threads/complaints.

 

I will order a couple resistors, but does that problem relate to my fog light switch now controlling my high beams?

 

We've seen all kinds of stupid shit wit LED headlights, as is covered in that thread. Unless you somehow cut the OEM harnesses, I'm going with, "YES".

Want to find out with no risk? Simply remove any LED and return the front lights to halogen (fogs/headlights/turn signals). Even if you just pop the connectors off and throw regular halogen bulbs in them outside the housings (don't let them melt shit).

You may only need one resistor if that resolves the issue. A lot of people get by with installing one on the passenger headlight. The whole point is, LEDs are low resistance and that circuit needs a certain amount of resistance to function properly. Without proper load, stupid shit happens.

I don't think I was impacted because I previously installed Diode Dynamics smartflash unit. But YMMV.

 

I do have a flasher installed for the switchback turn signals, but i'll try throwing some halogens in the headlights to see if that fixes it before ordering a resistor. I've always had LED fogs with no issues but that was run in conjunction with HID headlights. Thanks for the insight.

 

No worries. Let us know if it fails, maybe you're a special case or something we've never seen before.

IIRC, the fogs are also H4 bulbs, I would highly recommend tossing halogen bulbs in all four for this test. You just said yourself, they're on the same circuit (or so it appears to your eyes, I don't have 2003 wiring diagram in front of me). The whole problem with LEDs is the lack of load on the circuit, so if it's same circuit .... All the resistor does is essentially add additional resistance to the circuit, so things operate correctly again.

If you bought one of the knockoff/cheapie switchback units off scAmazon, you'd be the 5th or 6th person I've seen now have bullshit problems like this after theirs failed. It costs 1/3 as much as Diode Dynamics unit for a reason.

But think about it; relays require specific resistance. Relay is what's switching between these things. Too low resistance, relay coil doesn't fire as expected. What happens? You only switch as much as the coil in the relay will throw.

 

I will include a picture tomorrow of these unused mystery wires taped to my corner light harness. I'm just curious if the previous owner did anything goofy to get that HID kit to work.

 

Yeah, I'd be curious to see that. I wonder if they disabled DRL or something with those wires.

Wiring diagrams are linked in that megathread up there. Here, I'll save you a click, here's your 2003.

Look at the wire colors taped up.
The color code is in that wiring diagram.
Say one is red with green stripe, that would be annotated in the wiring diagram as R-G (for Red-GreenStripe).
Search that PDF for instances of "R-G" until you find something that seems logical.
Of course, R-G is just some bullshit I made up, but you may find light blue (which is "L" for lilac) with yellow stripe, you'd look for "L-Y" (Lilac-YellowStripe)
The hyphen is important. It's a bit harder for solid color wires, so zero in on striped wires.
You can skip any white wire with a black stripe, those are ground. Like, always.