The wiring diagram indicates a current timer/fuel solenoid on the 12C, 20B, 30B, 35C and 44A only (when used). You definitely have a fuel solenoid? If you do, I would try disconnecting that from its existing supply and powering it from another 12v source, putting an ammeter in series if possible. My multimeter has a 20A current capability, for example. Either way, the engine should then start and run without tripping the breaker if the fuel solenoid is the culprit. I tend to suspect the lift
pump is causing the excessive current draw. The fact that the engine will run when cold but will trip the breaker on a restart could mean the oil
pressure switch may still be energized due to residual oil
pressure during the restart allowing the current to the lift
pump. Again, you could isolate the lift pump and using another 12v source, measure its current draw. The other possible culprit is the field supply (P lead) to the alternator
. The alternator
has an internal regulator
so I would disconnect all leads to it to test that theory.