NDDan
Guest
Check back aways hear and follow tips for same problem on several models. Check voltage right at alternator and then on both sides of master circuit breaker in engine compartment and then both heavy terminals of master cab solinoid behind side counsel door. You should fine major voltage drop there some where. .1 volt drop is allowed for connections but zero is more normal. .2 volt drop is allowed for relays or solinoids but usually I see a bit more with max load on electrical. One guy recently noted that he added an extra wire from currant supply on starter to master breaker and then from other side of master breaker to master solinoid in cab. There is allways drop in wires and the longer the run and lighter the wire the worse it is at max electrical load. Quick way to check for ground problem is clamp set of jumper cables from cab to main frame. Good luck