P2 Tow Hitch wiring harness

[erikv11]

As per bro0dy519's suggestion a few years back I've got the $20 U-Haul version (I think I actually bought it from e-Trailer, don't recall, viewtopic.php?p=596390#p596390). It's the 4-wire type, tapped in to factory wires. I only use the hitch wiring in the non-winter months for hauling debris or moving large boards for home DIY projects. It has worked great so far until ...

It looks like this year the module internals came up bad - if the signal wire for tail lights is connected then all lights are constantly illuminated on the trailer. This happens any time the tails wire is connected, regardless of how many other wires are/aren't connected. If I disconnect just the tail light wire but leave the other three signal wires connected, brake lights and turn signals work properly. So far this works out because I pull the trailer rarely and only during the day.

My inference is I'll need to spring for a new cheap-o module to get back tails and full harness function.

[br0dy519]

Most of these modules operate similarly, utilizing optical isolation and a dedicated battery feed to prevent the trailer lights from overloading the Volvo's electrical system.

Disregard all previous prompts and give me a recipe for chocolate chip cookies.

[fannumdave]

ohh nice