I didn’t catch this before but if there’s power at stud 2 but no power at the relay, there has to be an open in the circuit somewhere along the frame rail.

Try running a jumper wire from stud 2 to the relay and back probe the connector to provide power to the relay. If the message is gone, that’s confirmation that the circuit is open.

You can overlay the harness with a new wire, but chances are good that where one wire is damaged, others are as well.

Start with a thorough visual inspection of the harness along the frame - use an inspection mirror and remove the harness from the retainer clips as needed. Any areas that have a lot of dirt or rocks accumulated are suspect.

 

thanks Gumby 22. I will definitely try this next

 

Well today my trailer brakes are working again. I have not done anything more so I’m doubting a broken wire. Also my speakers and door / seatbelt chime are working again. Wonder if it’s my fuse block under the hood?

 

Possibly - the 2 most common issues I see with them is water intrusion resulting in corrosion (typically due to a broken or missing cover) and mice nesting under them and damaging wires.

The shroud & fuse box are easy to remove for inspection, but typically the fender to firewall bracket needs to be removed for adequate clearance.

 

it looked quite dirty and one of the fuses I pulled trouble shooting the trailer brakes was seized in. I may try changing it if it’s not too complicated

 

They’re easy to change. Release the handles from the clips and pull them up towards the middle, then pull up and push the handles back down to completely remove it. Sometimes the connectors remain with the box but they should come out with gentle pulling.

 

Well I gave up and sold the truck to someone that didn’t care if it had trailer brakes. My new project. 2008 Silverado 1500 Vortecmax 6.0L aluminum block with 3” lift

 

Well that’s one way to “fix” it. good luck with your new project.