Lighting Problem - Reverse and Bed lights Stuck On

[Merica]

Any help appreciated. 2017 SCAB w/ BLIS tails

My reverse lights and bed lights in the third brake light are stuck on. It doesnt matter if my lights are on, off, bed light switch on/off, truck in reverse or drive. I was flagged down by someone on the highway to let me know they were stuck on yesterday and it hasnt stopped even with battery disconnect reset. What is going on? Thanks!

 

[smurfslayer]

Any mods; like reverse lights or some accessory using the reverse light or brake light as a signal?

 

[4x4TruckLEDs.com]

Is this the GJ Motorsports brake light? You probably pinched the harness somehow. Check your harness going from the brake light up to the front of your truck. Look for somewhere it is pinched/etc...

 

[Merica]

Any mods; like reverse lights or some accessory using the reverse light or brake light as a signal?

Only in the front, some A pillar cubes

 

[Merica]

Is this the GJ Motorsports brake light? You probably pinched the harness somehow. Check your harness going from the brake light up to the front of your truck. Look for somewhere it is pinched/etc...

Nah still stock third brake light. I do have some A pillar cubes but that's all

 

[4x4TruckLEDs.com]

So you only have front pillar cubes installed? No aftermarket reverse lights or anything? The cargo lights being on while you drive is a bit weird, because the truck doesn't let you turn your cargo lights on over a certain speed. However if you left them on, that's different. Sounds like you have a short somewhere is all. Have you done any other mods or electrical work besides your cube lights?

 

[smurfslayer]

cargo lights are -IIRC- a BCM controlled feature. I caused a BCM fault trying to power my reverse/chase lights off that circuit as a trigger - that should give you an idea how wimpy that circuit is. At first I thought I blew a fuse, but upon investigation I couldn’t find one relevant and non were blown; went to youtube and found some suggestions there may be a BCM trouble code.
Fired up for scan and sure enough, there was a DTC stored, I cleared it and was back to normal.

I think your problem sounds worse because there isn’t any triggering event- reverse lights or 3rd brake light, and the reverse circuit is on.

I foresee a stealership service department visit in your future.

 

[Merica]

So you only have front pillar cubes installed? No aftermarket reverse lights or anything? The cargo lights being on while you drive is a bit weird, because the truck doesn't let you turn your cargo lights on over a certain speed. However if you left them on, that's different. Sounds like you have a short somewhere is all. Have you done any other mods or electrical work besides your cube lights?

No other lights, but a dashcam hardwired in. I think to seat power if I remember correctly

 

[Merica]

cargo lights are -IIRC- a BCM controlled feature. I caused a BCM fault trying to power my reverse/chase lights off that circuit as a trigger - that should give you an idea how wimpy that circuit is. At first I thought I blew a fuse, but upon investigation I couldn’t find one relevant and non were blown; went to youtube and found some suggestions there may be a BCM trouble code.
Fired up for scan and sure enough, there was a DTC stored, I cleared it and was back to normal.

I think your problem sounds worse because there isn’t any triggering event- reverse lights or 3rd brake light, and the reverse circuit is on.

I foresee a stealership service department visit in your future.

I'll run a scan, but yeah dealer appointment made. Thanks

 

[Merica]

UPDATE:
Well it turns out the auxiliary harness shorted out and was causing all the problems. Covered by warranty. Wild