2014 freightliner coronado turn signal issuse

It's a ground problem.

 

looks like 2014 Coronado has multiplexing system too...)))))

 

Usually if something doesn't make sense like that it either the ground or two exposed wires are touching. The problem is it's always in a place where everything has been bundled up and wire tied.
Also those new freight liners have all that crap stuffed up above the visor. Which is a humongous pain in the butt.But I'd start around the hood.
It could also be a bad LCM.

 

Are you getting any bulkhead codes? That will tell you which ground wire is faulting out normally.

With it being a 2014 electrical issue, they should warranty it is the module is the issue. Freighliner does have a active recall on the "ACM: which is the fuse panel. It's causing all kinds of weird issues.

 

the acm is fuse panel ? acm --> aftertreatment control module. if this truck has multiplexing system like Cascadia then the problem is in SAM CAB. it must be reprogrammed with correct parameters. only freightliner dealer can do it.