No running lights, just brake & turn

[domer7]

I lost the running lights on my trailer. 2001 Chevy Silverado. I check the plug and have about 1-2 volts. Find separate trailer running lights fuse blown. Replace 15A fuse, now have 7-8 volts at plug. Plug trailer lights in, fuse blows. Replace the fuse and all of the trailer wiring with new harness, reattach the new ground wire. Strong signal at plug about 8 volts. As soon as I plug the trailer lights into the plug, the fuse blows. Does this indicate a short in the truck harness? I checked continuity in my round to flat adapter, checked continuity on the truck plug with the harness disconnected. Could it be a bad trailer light? Uses a combo bulb for running and brake.

Thanks, domer

 

[GA_Boater]

Welcome aboard.

I assume these are not LED lights. Take off the lens on both sides and take out the bulbs. See if the fuse still blows. I doubt it's on the truck end or the fuse would blow before you plug in the trailer harness - Possible, but unlikely.

 

[naturelover]

Seems odd you only have 7-8 volts at plug, shouldn't that be full battery voltage?

 

[gm280]

Yes, that is interesting. When you read that 7-8 volts are you reading that in reference to the truck ground or trailer ground? If trailer ground, that needs fixed as well. If truck ground you need to find out why it isn't battery voltage...