New to me Volvo truck with a Cummins ISM 370 and Eaton fuller 8 speed.
All the sudden gauges started going crazy
Ac clutch going in an out
Fan clutch in an out
I’ve checked out everything thing simple, looking for shorts etc. I’m new to working on big rigs so I’m learning (but work on my 06 Dodge common rail pretty often).
Each battery shows nearly 13 volts and there only a few months old. The truck cranks fast and starts right up.
But the volt gauge on the dash only is showing around 10, going up or down. Lights get dimmer, then brighter, heater fan barely will blow (not enough voltage).
Like something is drawing way to much power, or something in hindering it.
Wondering where to go from here