I messed with this this morning. Went to use it the other day to start a tractor and it quit on me. Took the covers off and looked around. Did some continuity tests and all seemed good. Plugged it in several times hooked to a battery and nothing. I was afraid to get too close to the transformer, didn't know if it held voltage. Got a battery cable and used it to ground the wiring in there just in case. More continuity tests, some love taps with a small hammer around the circuit breaker. Plugged it back in and it works again. I'm baffled!
Here's a manual on one close to it:
Here's a manual on one close to it: