P.B.S.

On my 1960 with a generator I can jump start and and the car starts fine. The gauge sits at 0 so I put a multi tester with the leads on the battery terminals and it reads 11.98 volts with the car running. This is also the same voltage as before trying to start. It seems to me it should an increase if it was charging. I have replaced the voltage regulator and harness to generator. What's next?

67vetteal

Put a multi meter to the Bat terminal of the Genny with the engine running. Use the "DC" setting. Voltage should read above 13 Volts if Genny is producing current. Also, Google and You Tube are very helpful when lost in the Woods. Al W.

62Jeff

Generators don't charge much if at all at idle. Raise the engine rpm to 2000 and check voltage at the battery.

65GGvert

Is the AC produced by the generator rectified in the generator or at the regulator? It's been a long time since I've worked with a generator and I don't recall if the output at the generator is measured in DC or AC.

jim lockwood

Start the engine and run it at 1500 - 2000 RPM.

With the Voltmeter connected to the generator Armature terminal and ground, use a test lead to momentarily ground the Field terminal. If the generator is working, the Voltage will jump up by a LOT..... 17 Volts or more would not be unusual.

The converse is also true. If nothing or very little happens, the generator is defective.

Jim

Easy Rhino

True. This is a major reason these were replaced in favor of alternators.

Check battery voltage terminal to terminal while the car is shut down, then recheck the same voltage with the car running at idle. Then, while watching the voltmeter, have someone slowly rev your engine to at least 2000 rpm and watch if voltage then increases above the battery's "at rest" voltage. This is not the most revealing test, but it is the simplest and a good place to start.

jim lockwood

Generator output is DC because of the action of the commutator.

Easy Rhino

Jim's answer is right - in a generator the commutator takes the (many) sine waves created in the armature and pics off the current at close to peak voltage as a result of commutator action - where the brushes pick off the current generated from the commutator sections. The commutator is the "slip rings" on which the brushes ride, but is sectioned (longitudinal sections separated by insulators).

In an alternator, instead of a commutator true 'slip rings' are used which results in picking up AC power which is then rectified into DC by a diode bridge circuit.

Both have a DC output, but arrive at the AC to DC conversion differently.