Headlights Suddenly Shutting Off While Driving

[Brendon]

I have a 2021 Jeep Wrangler Willys ordered new from the factory. It came with standard halogen lights. I tried to have the dealer install Mopar LED's when it came in. It installed them but couldn't get them to work because it did not have a code to flash them so re-installed the halogens. I purchased a harness and had a mechanic re-install the LEDS. They seemed to work fine. I rarely drive in the dark except during elk hunting season. Over the past 3 hunting seasons, the lights have suddenly and without any warning shut off. It has happened 3 times in the past 5 times I've driven the jeep. It seemed to only happen after driving for 20+ minutes. They black out for 3 to 5 seconds (although it seems like a lifetime at highway speeds). However, the last time, they went off after less than 10 minutes. There is no flickering or signs of a short or loose wire. Happens on smooth surfaces, paved highways. Turning the light knob on/off makes no difference and does not turn the lights back on -- they just come back on. Any ideas? This is a real safety issue.

Sponsored

 

[GATORB8]

It's just the lights themselves turning off, right? The dash is still in night mode with the lights indicator on?

 

[cripton805]

My guess is that he probably modified the harness somehow and it wasn't spliced correctly.

I would take it to a shop with good electrical experience.

I believe the 21s should have already come equipped to be able to run the LED headlights except for the Halo ring. That's the only thing to my knowledge that would require the code as the 21s were already prewired from the factory for the LED headlights.

Anyone else chime in?

 

[Brendon]

It's just the lights themselves turning off, right? The dash is still in night mode with the lights indicator on?

Yes

 

[Brendon]

My guess is that he probably modified the harness somehow and it wasn't spliced correctly.

I would take it to a shop with good electrical experience.

I believe the 21s should have already come equipped to be able to run the LED headlights except for the Halo ring. That's the only thing to my knowledge that would require the code as the 21s were already prewired from the factory for the LED headlights.

Anyone else chime in?

The harness was not modified. It was installed directly from the supplier. Not sure on the LED installation and code. All I know is they were installed and taken out when there was no code available.

 

[BenDiesel]

you could get a tazer jl and have it set the computer to led lights.

 

[Brendon]

you could get a tazer jl and have it set the computer to led lights.

I'm looking at that option but waiting on the harness supplier for its input. So far, they say they have never had this issue but are looking into it

 

[PrimeTime4370]

Just spitballing here and, someone can correct me if I'm wrong. If the BCM is still set for halogen lights it may be pushing more wattage and overheating the LEDS?

 

[BenDiesel]

Both headlights should work of a "12" volt system. The computer monitor the amp draw onthe circuit. Reg Hal light have a higher amp draw then led. So having it set to reg light the comp.is expecting a 5 ish amp draw when a led only draws 1. That freaks the computer out. Allot of aftermarket led will put a resistor inline some were to trick the computer into seeing the higher amp draw.

 

[Brendon]

Both headlights should work of a "12" volt system. The computer monitor the amp draw onthe circuit. Reg Hal light have a higher amp draw then led. So having it set to reg light the comp.is expecting a 5 ish amp draw when a led only draws 1. That freaks the computer out. Allot of aftermarket led will put a resistor inline some were to trick the computer into seeing the higher amp draw.

Thanks for the insight but I have Mopar headlights, the same that I guess I should have ordered in the first place. The harness I purchased has "modules" that supposedly take care of all the problems others were experiencing with the LED modification e.g. no halos, lights flickering

 

[BenDiesel]

Thanks for the insight but I have Mopar headlights, the same that I guess I should have ordered in the first place. The harness I purchased has "modules" that supposedly take care of all the problems others were experiencing with the LED modification e.g. no halos, lights flickering

ya the moduel is likely a combination of a resistor with heatsink and a capacitor to help with power draw. even the mopar brand headlights have a lower draw then the halogen. there are a few different programmers that can change the setting in the factory computer to set it to led , which shouldnt require the harness adapter.

im going with a programmer for my rig as i want to add the front camera and auto highbeam sensors. might add blind spot.

 

[NeilP]

The harness was not modified. It was installed directly from the supplier. Not sure on the LED installation and code. All I know is they were installed and taken out when there was no code available.

Download the JScan app, buy license and necessary harnesses and then program the Jeep yourself.

 

[Bayrat]

Both headlights should work of a "12" volt system. The computer monitor the amp draw onthe circuit. Reg Hal light have a higher amp draw then led. So having it set to reg light the comp.is expecting a 5 ish amp draw when a led only draws 1. That freaks the computer out. Allot of aftermarket led will put a resistor inline some were to trick the computer into seeing the higher amp draw.

Exactly! I had to do this when I installed a FASS fuel system on my CUMMINS, although it was a relay I utilized. In order to trick the computer, I had to put a dummy load via a relay to make it appear that the lift pump (which I removed) was running.

 

[Brendon]

ya the moduel is likely a combination of a resistor with heatsink and a capacitor to help with power draw. even the mopar brand headlights have a lower draw then the halogen. there are a few different programmers that can change the setting in the factory computer to set it to led , which shouldnt require the harness adapter.

im going with a programmer for my rig as i want to add the front camera and auto highbeam sensors. might add blind spot.

I talked with the harness supplier today and they are sending me a new harness with OEM connectors and halo wire but no modules. I will need to have it scanned to change the ECM to LED. Hopefully this is the fix I need. Thanks for the advice.

 

[Brendon]

Download the JScan app, buy license and necessary harnesses and then program the Jeep yourself.

Just so I'm clear, what "necessary harnesses" are you talking about? Do I need any special cabling to connect my phone with the app to the jeep? Really appreciate all the help.

Sponsored