Taillights stay on

[David Olson]

Hi,
I got a 99 K1500 that has given me lots of small electrical issues. Today when I parked my truck at work the left side tailight would not turn off the other one did though so I’m wondering if that would just be that tailight that stayed on harness is bad? I’ve had a similar issue but it was both and that was trailer plug but I’m pretty stuck on this one. Anybody ever had this happen and no the fix?
Thanks David

 

[kennythewelder]

If its its staying on, then its getting power when it shouldnt be. So you need to figure out is it a brake light, or a running light. Brake light, could be the switch. Running light, a short some where. Ether way, you need to trace back the wires with a test light and figure out where the short is. May be in trailer wiring, maybe not.

 

[Erik the Awful]

I would suspect the taillight harness. The wiring on my Stepside was all dorked up from someone poorly installing a 6-pin trailer connector. Later on someone else then went in and tried to do some roadside repairs. I threw all that junk out and went to Pull-A-Part looking for a replacement harness. Every pickup had butchered wiring. The 1/2 ton Suburbans all had pristine wiring. I nabbed a Suburban harness and plugged it right in. Five-minute fix.