Fog Light/Aftermarket Headlight Troubleshooting

Hi All,

The headlights on my 2017 TRD Offroad were replaced with VLAND LED headlights by an autobody shop after my truck was rear ended into another car. I also upgraded to an aftermarket bumper which required me to order new fog lights (Diode Dynamics). My fog lights did not come in time to have the autobody shop install them and so I just installed them myself. No big deal.

Now here is the issue. The fog lights turn on/off with the headlights. They will not turn off with the fog light switch if the head lights are on. They also do not turn off when i switch on the hi-beams. The fog light indictor light in the dash still turns off and on as it should even though it is not reflective of the actual fog lights.

Yes I can take it back to the shop and have them fix it, but I am hoping it is something I can easily correct myself. I am working on the assumption something was mis-wired with the new head lights and is causing the issue.

Does anyone have any idea what would cause this/wear to start. I cant find an instruction manual online for the VLAND Headlights. Worst case I can wire the fogs into my Trigger controller, however I would prefer to retain the function of the OEM switch. (FYI, I did try to search for related topics, but could not find what I needed. Please feel free to direct me to another thread if this issue has been discussed.)

Thank you!

 

Looking at VLAND, the headlamps are plug and play. I would guess that somehow the foglamp plugs are swapped with a headlamp... does the low or high beam turn on with the fog?


To test, just turn on the park lamps and then the fog light switch. If you headlamps are on then the plug was swapped.

 

This was a smart idea, however not the case. I appreciate the feedback.

 

Then some tracing will have to be done...



The blue box at the top is the Main Body ECU.

 

Will see if I can trace the wires tomorrow

 

To start have you looked at the wiring from the Aftermarket headlights and the Fog lights?
It seems the fogs and headlights are same wire.
Also, is the fog ON indicator the correct one or is it being confused with the headlight on indicator?

Another issue is when Highs are selected the Lows remain ON.

 

So your body shop put in a cheap copy of the OEM product and it's not working as expected in a vehicle widely known for how sensitive it can be with electronics. If it were mine I'd take it back and insist they replace those headlights with real Toyota units.

 

I need to do some more digging when it comes to the wiring, havent had the chance to really trace it yet.

I can assure you I am not confusing the the fog and headlight indicators.

Gotta double check the highbeam/low beam to see if the lows shut off.

 

Think fogs don't work when highs are on, make sure the lever is pulled back.

 

I appreciate the concern although this was not a malicious or fraudulent error from my bodyshop. My truck did not come with LEDs and he was going to replace the headlights with the OEM halogens. I had asked to upgrade to LEDs. Now I was annoyed that when I asked to upgrade to OEM LEDs, it was only after he had installed the VLANDs that I found out he was having trouble source the OEM LEDs. If I had know that I would have gone with Morimotos. To be honest though, the VLAND headlights look great and have been performing well (other than this fog light error).

The shop has done lots of work on my families vehicles and the owners attention to detail (as far as body work is concerned) is top notch. They installed new backwoods adventure mod bumpers for me during this process and the work they did is extremely clean, with no extra cost to me. The shop owner has said I can bring the truck back and he will fix the fog lights. That is not the most convenient option for me, however i will drop it off next week if I cant figure it out myself this weekend.

 

Correct, they should turn off when the highs are on. Currently they stay on.

 

Ok to address these 2 points now i have taken another look.

I have figured out which function each plug in the back of the head light controls. However when I unplug the wire that should lead to the fog lamps, the fogs stay on.

To address the second point, yes the low beams stay on when the highbeams turn on. To my knowledge this is how they are supposed to work?

 

Tracing the wiring past where it enters the factory sheathing is about impossible. I would prefer not to tear into that.

I appreciate all the feedback I have received so far. Turning bolts is fine, but I really struggle with the factory wiring.

 

Second Point: Correct
First point: Should = vague

 

Fair point. All the other light functions work properly when the said connector is unplugged. For this reason I assume this is the connector that “should” somehow be connected to the fog lights. That being said it is not a direct line straight to the fogs, it runs back in to the factory sheathing. The wires are not the same color as the wires that go to the fog light.

 

There are 2 plugs from the halogen headlights that are the same, but control different lights. Those might have gotten swapped. I ran into a similar issue when swapping in my Morimotos. I do have a 21 Off-Road that had the drl L's, but I do not believe those are powered by the other harness I'm referring to.

Low beams and high beams should both be on when highs are activated (though I don't know anything about the headlights you have installed specifically), but the factory behavior for the fogs is that they disable when the highs are enabled. I installed a BriteBox to keep them on with the highs.

 

Not helping...

 

How? This absolutely sounds like it could be the issue, and I confirmed how the factory fog functionality should perform.

 

From a head light only perspective, they are functioning properly. DRLs work by them selves, blinkers work, low beams work, and high beams work (low beams stay on as they should).

The fogs do not turn off when the high beams are engaged and cant be manually turned off when the lowbeams are engaged. The fog lights still come on without the low beams when the park lights are on, however still cant be turned off manually.

 

Fog lights OEM, only turn on AFTER Parking/Tail is selected.