Uh oh...voltage crash and now won't turn over

OK. In that case your "quick test" needs to be a bit different. You can test this several ways, which will, depending, test the alternator, and or the field wiring as well.

1....Charge the battery. No sense doing anything without this. You can "dirty quick" test the battery after you get it charged by jumpering the starter relay as shown in the posts above. If it cranks nice and fast, you are OK

2....Unhook the GREEN field wire at the alternator. Clip that field terminal to ground. Now turn the key to "run" and measure voltage at the BLUE alternator field terminal. This should be very close to "same as battery" and at least 12V or more

3....In subdued light, if possible, unconnect and reconnect your clip on the other alternator field. You should see a small spark each time, which shows the alternator field is drawing current

4....Start the engine, and with a meter on the battery, slowly bring up RPM. Don't let it climb above 16V but see if it does climb

5...If the voltage doesn't climb much or at all, shift your multimeter to the alternator big output stud, and again, bring up RPM. If the stud voltage goes way high, then there is an open/ poor connection between alternator and battery "the charge line."

6...If voltage does NOT climb, the alternator is not charging. First thing to do is pull it off and remove brushes and inspect. They may be worn, broken, greasy, stuck etc. If they appear OK reinstall the brushes and check resistance between the field terminals. Should be a low reading "a couple or 4" ohms.

If field is open, replace alternator. If brushes are bad you MAY be able to buy a set. Take the old ones with you. Otherwise, if the tests above showed no charge, replace the alternator

=================================

7......If in the above tests the voltage DID climb at the battery, now we need to test the field wiring. To do that, reconnect your field wires, and disconnect the VR connector. Make SURE the VR is firmly mounted and GROUNDED. Remove, scrape around the bolt holes, and remount with star lock washers.

Push / pull the VR connector several times to "feel" for tightness and to scrub the terminals. Inspect with a light are they clean? Reinstall, see if it charges

If not

8.........We are again going to jumper the field "full field" as in earlier tests, this time using the VR wiring. Remove the BLUE field terminal at the alternator, and clip that field alternator terminal to ground. Now devise a way to jumper across the to VR connector terminals, machine screws, etc.

9....Again monitor battery, start and run, bring up RPM. Voltage should climb. If not and if the alternator worked in earlier tests, replace the VR