Issue with tail lights

[Tron]

Hey,
I'm having an issue with my tail lights. Couldn't find anyone with the same issue previously. Appreciate any help. Thanks.

The tail lights don't come on unless I press the brake pedal. Then when I press the brake pedal the tail lights go out, no brake lights. Both turn signals flash at the same time when signaling as well.

I have tried a few headlight switchs and interior wheel switches and nothing. Took out my trailer harness as well and nothing.

Vehicle info:
1994 K2500 6.5 Diesel - Ext. Cab, long box.
Tail light bulb are all LED.

Thanks.

 

[97C1500TJ]

Hey,
I'm having an issue with my tail lights. Couldn't find anyone with the same issue previously. Appreciate any help. Thanks.

The tail lights don't come on unless I press the brake pedal. Then when I press the brake pedal the tail lights go out, no brake lights. Both turn signals flash at the same time when signaling as well.

I have tried a few headlight switchs and interior wheel switches and nothing. Took out my trailer harness as well and nothing.

Vehicle info:
1994 K2500 6.5 Diesel - Ext. Cab, long box.
Tail light bulb are all LED.

Thanks.

I had a similar problem a few months back and mine was a bad ground. It was the one behind the rear bumper to be specific. It just corroded off after 23 years. My turn signals would do the same thing.

 

[Dover]

I had a similar problem a few months back and mine was a bad ground. It was the one behind the rear bumper to be specific. It just corroded off after 23 years. My turn signals would do the same thing.

Second that, most likely bad ground or badly corroded sockets in one or both taillights. Corrosion can make current go all sorts of odd places.


Sent from my iPhone using Tapatalk

 

[97C1500TJ]

What I’d do is check that ground and go ahead and swap out those taillight circuit boards for some new ones if they are original. It’ll save you from getting a ticket in the long run.

 

[frito-bandito]

X3 on one of the grounds on the rear of the frame, my 99 C2500 did the same thing

 

[Nad_Yvalhosert]

What LED's are you using? The sockets are "wired" very specifically and if you aren't using 3157CK LED's, the lights will not work properly.
Also, LED's are polarity specific, unlike incandescent bulbs.
Remove the lens, remove the circuit board, remove the LED's and plug the boards back in. Test for power and make a schematic.