2002 Volvo D12 right turn light issue

Try to unplug the marker/turn lights one at a time, then activate the turn signal. Maybe one of those lights has a short in it. So if you unplug one and it starts working the others, then u change that one light out.

... it’s a place to start...

 

Hmm, that’s interesting. If you had a test light, you could unplug the pigtail to the trailer and turn on the right turn signal and check for power coming out of the pigtail. This test will check to see if the truck is giving the command to the trailer or not.

 

Take it to the dealer and have them check the body computer because the body computer controls the turn signals.

 

Have you tested every fuse and replaced if bad?

 

Try this website to maybe get an idea. It’s got like every wire diagram for gen 1 Volvo’s

Schematics