Troubleshooting external Voltage Regulator --Help

[silverc4s]

I am trying to determine if my early voltage regulator is faulty. The car is a 1970 2.2 S, the alternator is a Motorola SEV almost new, removed and tested today. Local Alternator rebuilder says alt is good.

The batteries are two Braille AGM units, also virtually new and charged reading about 13.3 volts.
The last time the car was on the road, it stopped charging and ran out of juice after about 35 miles of driving.

The car will start and run now, but the indications of charging are intermittent. I want to remove the regulator, a rectangular aluminum canned device on the engine compartment electrical panel.

Can anyone give me a clue what to test for / look for?

Thanks all.

[savaden]

Basically, you test a regulator by confirming its function when installed in the circuit. You cannot generally test a regulator out of the circuit with an Ohmmeter. The only thing you can easily check in circuit is the maximum charging voltage, which should be about 14.7 V I think, measured at the battery.

SV

[silverc4s]

I have done that. Performance was intermittent looking at it in the garage. Not exactly confidence inspiring. I am hoping that this early regulator is not electronic, but more relay based and possibly repairable.

[silverc4s]

Parts manual calls out an Oscillating Regulator for the Motorola alternator. Pt no. 901.603.206.11
It calls for a Element Regulator for the Bosch alternator. Pt no. 901.603.206.02

So I assume if I have the Motorola alternator I must use the 206.11 Regulator.

[304065]

Bill, the reason the Factory says "alternator and regulator must be from the same manufacturer" is that the "set-point" of the regulator, or the charging voltage it will produce at the B+ terminal, is a function of the design of the alternator and the voltage and current sent from the DF terminal of the regulator to the alternator's rotor.

The DF voltage varies among makes to get to the same set-point, enough to make the factory say that back then.

The way you measure this is by measuring with a voltmeter, the voltage at the battery terminals with the engine running and the generator light OUT. Usually it will go out slightly above idle on the first start. What is your reading?

Also. . . AGM (absorbed glass mat) batteries require a different, higher charging voltage. What charging voltage does your manufacturer recommend?