1997 Kenworth t800 flasher problem need help

Just rear turn signals, not front as well? Both sides or just one?

 

One side or both sides?

 

Might be speaking out of my but on them older trucks with that signalstat contraption for turn signals sometimes goes funky.

 

No, that’s where I’d start too. Because it controls indicators and 4-way in the one unit.

 

The front not doing it too kind of puzzles me though. I'd need to see a schematic to see if they're on the same circuit or not.

 

I just remember the nightmares from them things, just in the right place for that coffee to splash on with a huge bump, but it can be my dementia