Hi All, I got a bit of a problem with my Western Star, when air pressure is full it starts great. if sitting for a weekend and air runs out, when go to start the fan is locked and has a hell of a time starting. I did a rebuild on the Kysor fan clutch and checked solenoid, both working fine but I do not get that little air release when key turned on before starting which it used to. would this be a AC switch?
AC trinary switch could power the fan clutch if it's equipped with red dot AC. The bigger problem is your starter struggling to crank a fan blade. I think you've got a poor connection somewhere or weak batteries. Good luck
What engine?