Is There a Way to Reset the Curt Converter Box on Vehicle Wiring Harness on 2003 BMW 325i Wagon

Updated 03/30/2016 | Published 03/27/2016

Question:

I have this part installed on my 2003 BMW 325I wagon. I use it to convert the tail lights for a small utility trailer. It worked fine for a few years then the last time I hooked up the trailer, I noticed that when my cars headlights are on, the blinkers on the trailer dont work. If I turn off the cars lights, the turn signals DO work. I probed the wires before the converter box and I get full intensity on the test light. But when I probe each wire after the converter box while the headlights are on, I get a almost undetectable intensity change on my LED tester. When I turn off the headlights I get full intensity from the turn signal on the test probe. I think my converter box is bad. Is there a way to reset the box by pulling the fuse, or is there a more heavy duty converter that is more reliable? I have had these converters fail before on other cars and they seem to be temperamental. But maybe it is just bad luck for me. BTW, I did not buy the part from your site, but am seeking your advise for a replacement because I have heard good things about etrailer.

asked by: Jerry B

Expert Reply:

It does sound like your converter box may be defective. Unfortunately, there is no way to reset the converter. I recommend trying to relocate the ground of the converter to see if this provides a solution to your problem. Grounding issues can show themselves in strange ways.

If relocating the ground doesn't fix your issue, I recommend replacing the wiring harness. For European cars like your BMW 325i Wagon, we've found we have the best success with the Upgraded Circuit Protected ModuLite with 4 Pole Harness and Hardwire Kit # C59496. This wiring harness upgrade will install using the existing power wire ran on your vehicle for the previous harness. I have attached a review video of this wiring harness for you.

I have attached the installation instructions for the # C59496 for you.

expert reply by: Victoria B