When I turn on my running lights with my trailer hooked up (and only if I turn the running lights on) my reverse lights light up faintly (not full power) and the truck dings and tells me somthing is wrong with the connection
Anyone have any ideas what could be wrong with the wiring on my truck?

It's not the trailer because I just redid all the wiring myself And used a testing unit to make sure the trailer is wire right. the truck works with the tester too but I didn't wire the truck I had a shop do it. could it be cross wired somewhere on the truck to make the reverse light faintly light up.