Side markers do not work after installing led tail lights

[luke2pl]

Just installed truck lite led tail lights. After installation noticed that left side markers (front and rear only on left side) don’t work. The right side markers work great. The left side markers (front marker has stock bulb the rear is led) don’t. Attached pictures.
I check ground on both lights new installed tail lights seemed to be grounded.

thinking that front left side marker bulb (stock bulb) might be causing it. However before installing these led tail lights everything worked good. Any ideas…

 

[Thunderbirds]

Just installed truck lite led tail lights. After installation noticed that left side markers (front and rear only on left side) don’t work. The right side markers work great. The left side markers (front marker has stock bulb the rear is led) don’t. Attached pictures.
I check ground on both lights new installed tail lights seemed to be grounded.

thinking that front left side marker bulb (stock bulb) might be causing it. However before installing these led tail lights everything worked good. Any ideas…

Are you using plastic lenses on a metal tail light body? The Army figured out that wouldn't work:



But why the side markers stop, IDK. Maybe a grounding issue?

 

[Dieselmeister]

Blown fuse or disconnected wire. Do you have a voltmeter or 24 volt test light? I would start working my way back from the marker light, and see where the voltage gets lost? Could be an open ground, or open positive. Do you have access to the wiring diagrams in the TM?

 

[luke2pl]

Blown fuse or disconnected wire. Do you have a voltmeter or 24 volt test light? I would start working my way back from the marker light, and see where the voltage gets lost? Could be an open ground, or open positive. Do you have access to the wiring diagrams in the TM?

I was told Humvees don’t have fuses. I checked the grounds on both lights. It’s all grounded. Markers seem to be grounded, two new lights look grounded. I was thinking the light bulb in the front side marker is causing all this. I bought replacement marker it shipped today.

 

[luke2pl]

Are you using plastic lenses on a metal tail light body? The Army figured out that wouldn't work:

View attachment 930412

But why the side markers stop, IDK. Maybe a grounding issue?

Are you using plastic lenses on a metal tail light body? The Army figured out that wouldn't work:

View attachment 930412

But why the side markers stop, IDK. Maybe a grounding issue?

They are plastic lenses. I am hopeful that the light bulb on the passenger front is causing all this. I was told that truck light leds require flash box unit today. I am unsure how that would affect side markers. I will try to put my old lights back to see if there is difference.