Location of diodes in the Alternator Restart system?

[Rick Erwin]

Originally Posted by wslade2

1. Perhaps the next test is not a voltage test of various wiring junctures but an ammeter test of the alternator restart circuit. See how much or if any current flowing through when button pressed.

2. Also, another next step might be a test of the system switches per the procedure outlined by others here to see how the system works.

3. Or was dysfunction on a test what started the dive into probing the circuit?

see attached

wslade2, thank you for lending some mental energy to this circuit. Your thought process seems sound.

1. Monday, I'll check the amperage load while the circuit is energized. Maybe it's not volts that are needed to restart an alternator, ... maybe it's amps?

2. The switch in the restart system is good. To eliminate the switch as a culprit, I have even bypassed the switch during testing, but to no avail.

The two diodes in the system, as well as the resistor, all check within specifications. The alternator switches are good. The voltage regulators are good. The entire electrical system works great ... except for this Alternator Restart circuit.

Is it to be expected that voltage should drop to zero when the dry-cell batteries are connected to the alternator's field terminal? Or, is there something wrong inside the seemingly good alternator/s?

3. Yes, all this started when the checklist specified test failed to restart the alternator/s. The checklist specifies in the event the alternators do not restart, reduce the electrical load, and try again. I attempted that, without success.

Thanks again,

I'll report back Monday evening ...

Rick