Peterbilt 379 Right Turn Signal isn’t working

I'd almost bet money you've got a broken ground. Check and see if all your right blinkers illuminate. If there is one bad fix it and I bet your problem goes away

 

One my 01 pete anytime my blinkers act up the first thing I check is my taillights and 99.999% of the time one is burned out or broken wire

 

Was there any update on this? I'm having a similar issue, no right turns at all no brake lights on tractor and no indicator light on the dash. I've checked all fuses and connections and even unplugged the main harnesses on the firewall to eliminate all out side possibilities. The turn signal switch was replaced recently so I'm thinking the module under the dash is the problem.

 

I have a 2027 589 and my right turn signal on my trailer will not blink it works on the truck. I have checked the pig tail and no power there. This is the Second time I have had this exact problem peterbilt said they changed a fuse and it worked for a little over a month. I have changed the fuse again but still not working. Any help would be nice.

 

If you checked the pigtail, you need to work backwards. Check the socket at the rear of your cab to rule out the pigtail. Then check the wires going into the back of the socket.

 

I have unplugged it and tested truck side and had no power

 

OK now you know the problem is with the truck. I am assuming rhat all the lights work on the truck correct?
Start in the fuse box. I could be the harness, that runs to the back of the truck. I would check that where it comes in to the firewall.