Puzzled by light bar on trailer

[JAL51974]

My trailer lights all work as they should except the light bar at the rear which has me puzzled. It only lights when my tow vehicle is in gear . All the other running lamps light when the trailer harness is plugged into the truck harness. The tow vehicle is a 2000 GMC Sonoma. That light bar at the rear is powered by the correct wire, running light circuit on the right side of the trailer (viewing it from the rear of the trailer). Any ideas? I thought it should light up along with all the other running lights whether or not the truck is in gear? Is it something related to that particular truck? With my truck, the lights are always on day or night without manually switching them ON.

Joe

 

[rndn]

Re: Puzzled by light bar on trailer

It sounds like it is getting it's power from the daytime running lights?

 

[Silvertip]

Re: Puzzled by light bar on trailer

It probably has a bad ground. And if its connected to the tail lights it is indeed connected to the right circuit. If the tail lights work the trailer is grounded. So either it does not have a good power connection or it has a bad ground.

 

[JAL51974]

Re: Puzzled by light bar on trailer

Power connection is correct and I checked the ground last year. I ran it today and it only works if I manually turn on the lights on the truck. The other running lights on the trailer work the same as the truck lights...on automatically. I will double check the connections though to be sure.