here is another strange one

[Allensr]

Getting ready to take a long ride with my dog, him in trailer, when I noticed my right tail light was on on the trailer. The issue is the key was off on the Spyder. Getting about 8 volts out of trailer connection on the leg that goes to right light. There are no lights on Spyder and the voltage goes away when I remove fuse marked trailer. Hitch and controller installed by dealer about 3 weeks ago. Can it be anything other than a bad controller? Local dealer cant see me until Oct 2. Trip on hold.

[billybovine]

Getting ready to take a long ride with my dog, him in trailer, when I noticed my right tail light was on on the trailer. The issue is the key was off on the Spyder. Getting about 8 volts out of trailer connection on the leg that goes to right light. There are no lights on Spyder and the voltage goes away when I remove fuse marked trailer. Hitch and controller installed by dealer about 3 weeks ago. Can it be anything other than a bad controller? Local dealer cant see me until Oct 2. Trip on hold.

I think you made a good guess. The isolator/converter module appears to be bad.