Trailer wire problems

[DLeach]

Finally bought my new plug for my trailer to convert the current 6 pin plug to the 7 pin. First thing I did was check my friends Exiss 20 ft stock combo. Everything worked perfect. Then tried to match most of the wires on mine and with the truck off,running lights and everything off, when i plug in the trailer plug my reverse and running lights come on on my truck. So then checked out my diagram on my plug cover on truck and seems like everything is good. My trailer came with a diagram for its wiring and it looks right too. Then i took a 12v source and tested my trailer wiring with 2 test leads... everything looked good too. What would cause my running lights on my truck to come on when i plug in my trailer plug? Also if i try to check the brakes all the lights go off... ... Im about ready to rip all the wiring off the trailer and start over... but the trailer is brand new... . what gives... ...

 

[B.G. Smith]

Weird wires

Ran into a similar problem, was putting the plug in upside down, does strange things to the lights. bg

 

[clem]

You did not say what kind of trailer you have. If the trailer has a bat. on board for 12v power you might have got the trailer charge line on the trailer swithed with the trailer running lights in the trailer connector. Not hard to do as you look at the trailer plug the pins are 180 out. Have made that mistake, you have to wire by the color code and pin # not by the location as viewed. Hope this helps

Have done this myself makes you fell real dunb