Troubleshooting Non-Working Diode Wiring Kit On A 2015 Fiat 500

Question:

I have a roadmaster high-powered diode wiring kit that has been working for two years. It all of a sudden stopped working. Where do I begin to troubleshoot? turn signals don’t work brake lights don’t work running lights don’t work nothing.

asked by: Roberto R

Expert Reply:

If nothing at all is working then the ground wire for your Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit # RM-15267 is likely the issue. I recommend checking that it's making a good connection to the frame of the vehicle and isn't starting to corrode. If that isn't the issue then you'll need to connect to the motorhome or another vehicle with a 7-way connector and then put on your light signal (you can just start with running lights) and then trace the wires back starting at the motorhome connector with a tester # PTW2993 to see where the power is being lost or if there's any loose connections or damage to the wires.

If you don't find any damage to the wires and you have power up to the diodes but not past them then your diodes will need to be replaced with part # RM-790.

expert reply by: Kevin C