voltage regulator testing

[DAH]

I have a 1967 Dodhe Coronet 440 with the 318 engine. I am having the problem that the voltage at the battery with the car running is only showing around 10 VCD. The battery is good and does hold a full charge. Can someone tell me how to test the voltage regulator with a multimeter when removed from the car? Also is there a way to test the alternator? I don't want to replace good parts only the ones that are working.

 

[DAH]

I meant to say onlt the parts that aren't working.

 

[twecomm]

What's the battery voltage without car running ?

 

[RJRENTON]

I have a 1967 Dodhe Coronet 440 with the 318 engine. I am having the problem that the voltage at the battery with the car running is only showing around 10 VCD. The battery is good and does hold a full charge. Can someone tell me how to test the voltage regulator with a multimeter when removed from the car? Also is there a way to test the alternator? I don't want to replace good parts only the ones that are working.

If your vehicle is original, you have/had a mechanical voltage regulator. REPLACE it with the newer ELECTRONIC VOLTAGE REGULATOR as a directly replacement. It is likely that the original alternator is 37 amp, round back design with one wire from the voltage regulator to the alternators rotating field (green wire). The electronic voltage regulator is available on line for approximately $25. If the original alternator has been up graded to a isolated field unit (1970 and newer) using a Mopar electronic voltage regulator, make sure everything is grounded and all wires are tight and corrosion free including bulkhead connectors. If the system voltage is still low, replace the voltage regulator. It is NOT LIKELY that the alternator has a bad diode.
Just my opinion and thoughts....
BOB RENTON

 

[DAH]

Hello Bob. Thank you for responding. My car is all origina as far as I know although I bought it used so if parts were replaced before i got it I don't know. The voltage regulator is rectanglar. The case has two connectors. One is marked FLD and the other is IGN. The FLD post has a small green wire and the IGN post has a slide on connector. Here are pictures of the voltage regulator and where it attaches to the firewall. Front and back of the alternator.

 

[twecomm]

Again... What's the battery voltage without car running ?

 

[DAH]

When fully charge 13.55 volts.

 

[DAH]

With the car running the vdc is only 10.5.

 

[RemCharger]

Hello Bob. Thank you for responding. My car is all origina as far as I know although I bought it used so if parts were replaced before i got it I don't know. The voltage regulator is rectanglar. The case has two connectors. One is marked FLD and the other is IGN. The FLD post has a small green wire and the IGN post has a slide on connector. Here are pictures of the voltage regulator and where it attaches to the firewall. Front and back of the alternator.

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Pop the cover on your regulator and have a look. And or post pics

 

[DAH]

Here are pics of the regulator, inside and back.

 

[R413]

Put a voltmeter across the battery posts. With the car running approx 1200 RPM connect those 2 wires that go to the voltage regulator for just 3 seconds and read the voltage output.

This is called "full fielding" the alternator. It tells you it's maximum output.
If the voltage goes over 15 that's good, if under 15 that the alternator needs repaired.

The voltage regulator needs to be grounded to function, the 2 bolts will do that just fine, do not start sanding the paint off the firewall.

It has been my experience that the new solid state replacement regulators for 1961-1969 mopars don't work right for very long before they go to full charge all the time.

 

[DAH]

I don't have anyone to help so I can't do all that.

 

[RemCharger]

Here are pics of the regulator, inside and back.

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I was wondering if one of these 2 wires were burnt. Also if the points are stuck

 

[dadsbee]

Sure you can......

Stick the vm leads into the battery terminals. Start the car... hold the two wires together as noted above and watch the meter.

 

[R413]

I don't have anyone to help so I can't do all that.

You can do this by yourself.

Start car, raise idle with fast idle cam or put a piece of something between idle stop screw and throttle.

Connect meter and place it where you can see it.

Now hold the two wores together for 3 seconds and rear meter.

Disconnect wores.

Turn off car.