Trailer light help??

[jmvotto]

I have a 2012 boat mate trailer
The right side lights tail light and turn signals work
Left side does not

All running lights work both sides

Checked wires looks good

Could the 5 pin adapter to the gm round plug go bad on just one side ?

Any help would be great

[jstenger]

Did you check the tow vehicle? If not, check that. Then plug just the adapter in and check that. You need to narrow things down.

[jmvotto]

Tow vehicle is fine

[sivs1]

I had the same issue, turned out the left and right on the tow vehicle had different fuses.

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[jmvotto]

Adapter is fine. Really tough to isolate where the trailer fuses are

I did check but no issues there either

[smorris7]

This happened on my 12 Mojo. It ended up being the 5 pin round adapter wasn't making good contact with tow vehicle. Took some sandpaper and roughed up connections and left side works again.

[pridekit]

Which GM vehicle is it? I can help with the 07-13 silverados (I have one). The fuses for towing are in the engine bay. Autozone carries a tester that plugs into the 7 to 4 pin adapter (or the 4 pin plug on your vehicle), it has lights that will come on to confirm that everything is working correctly in the tow vehicle.

[yearround]

I have a Ram 1500, I had the similar issue, the running lights worked, but the turn/brake on one side (rt or lt i forget) did not work. I thought it was the boat trailer, til i hooked up a couple of my other trailers and the same side did not work, but they lights all worked on another vehicle. the ram has fuses for trailer that are different than other fuses. after a lot of looking, my brother said RTFM, we found the fuse pattern in the manual and got the fuse replaced. it was a mini micro fuse and hard to physically locate one to buy.

[jstenger]

I believe jmvotto said his truck and adapter were fine. This leads me to believe it is a loose or dirty connection at the light or trailer plug.

[White94RX]

This is where a good digital volt/ohm meter comes in handy. Along with some good troubleshooting. I'm an auto tech by trade, so this would be easy for me to isolate. If some lights work, that tells me the ground connection is good. Next you'll need to test one thing at a time. First test your truck without the adapter. Then plug in the adapter and test it. If that checks out, then you go to the lights themselves. Should be very simple to pinpoint where the issue lies.