Does Converter in 6-Diode Tow Bar Wiring Kit Prevent Back Feeding Installed on 2014 Chevy Sonic

Updated 06/02/2014 | Published 05/30/2014

Question:

Im updating my setup. I have a Coachmen built motorhome with combined lights, Blue Ox Aladdin towbar, towing a 2003 Jeep Wrangler with an installed Roadmaster Add A Brake. The installer didnt use a brake relay so the lights on the Jeep didnt blink if the brake was on. I was never really happy about that. I recently bought the parts to fit my Chevy Sonic baseplate, 2nd vehicle kit,fuse defeat, wiring. I purchased wiring kit part # 154-792-118158 rather than use separate bulbs or combining the lights on the Sonic. This method also avoids a brake relay which would be difficult to fit because of the limited room under the dash. One reviewer of this wiring kit reported a 3V drop when using the converter, which would be consistent with using two diodes in series. So my question is, on the MOTORHOME side of the wiring, is it necessary downstream of the converter to connect through the upstream side of the diode for the car wiring or can it safely be tied into the lights below the diode? In other words, does the TowReady converter prevent backfeed to the motorhome without a supplemental diode? I understand the car wiring will still need a diode in the line to protect the car. If my question isnt clear, I can upload a diagram. Thanks!

asked by: John G

Helpful Expert Reply:

The converter contained in diode kit # 154-792-118158 offers minimal at best protection against backfeeding. That is one of the purposes of the included diodes. A drop in voltage can also be attributed to the length of the wiring it has to travel and the resistance change when adding tow bar wiring like a diode kit. Provided the lights operate correctly once the kit is installed, a slight voltage drop, though expected, should not prevent the system from working properly.

I do recommend installing a brake light relay, # RM-88400, on the Jeep if you still have it. Otherwise, without turn signals, you could potentially be ticketed and other drivers may not notice you are turning.

expert reply by: Michael H