Okay heres the problem. I have a 97 Dodge Ram with the factory towing package. When I hook my trailer to it using the factory 7 pin connector I have all lights working except the running lights. Anyone have any ideas what to look for to fix this?

Viper

 

Check your grounds on your trailer. Seems like the majority of trailer light issues can be traced back to bad grounds.
If you have a volt meter you can also check your truck end and see if you have voltage at the connector.

This page here also shows you pin-outs to help trouble shoot the plug itself.
http://www.marksrv.com/wiring.htm

Hope this helps.

 

Ensure the fuse for the trailer harness is not blown. My 01 the lights on the trailer didn't work because the fuse was blown.

 

That's the first thing I would check. They often don't put a heavy enough fuse in for the trailer lights.

The second thing I would check would be that the plug on the trailer is wired correctly. Sometimes they have to be rewired to match up with the truck's wiring.

If both of those are good, then I would check the wiring (trailer first) for shorts.

 

roms right... alot of times companys and trailer building businesses will wire the trailor and plug up for the most standerdized wiring possible... most ive seen are exact for GM connector wiring... witch is different for our trucks.. easy to troubleshoot with the use of digital multi meter and a buddy in the cab switching everthing on and off for you... defenatly check all the fuzes first...easiest... u can also trace the wiring harness for the plug through the truck to ensure that there isnt any breaks shorts or frays... IIRC .. the park light wire should run up and connect to the bundle that ends up going to the headlight switch... ie giving you power for the park lights etc etc. now if the factory fuze is in there working good for the trucks park..now there is a larger draw off that circuit .. and causing a secondary fuze to blow...primary wont blow b/c its better and safer to run the truck with the park/running lights on than it is the trailer...