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Ever since I have owned my car, I have had issues with the charging system. I have gone though countless alternators and batteries. I tired converting to a 1 wire alternator setup with the regulator attached on the side, still didn't fix it. The car will say charged for awhile after changing the alternator or battery but eventually it gets to the point that the car cuts out while driving. Today I charged the battery up and drove it about a mile down the street, when I turned it off and tried to restart it the battery was completely dead. Does anyone have an idea whats up?
 

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In the 67 service manual it suggests that you test the charging system after new parts are installed. If the voltage reg is bad it will cause the alternator to go bad. If the alternator is bad it will cause the voltage reg to go bad and the battery. it will either over charge (FRY) or drain it. If the battery is bad it will cause the alternator to go bad... It's like going in circles.




You can test everything with one of these.

 

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Your alternator should be putting out 13.5 to 14.5 volts but thus requires that your voltage regulator is functioning properly.

Make sure the connections on your battery are clean and tight as well as the ground from the battery to the engine block and the cable from the battery to the starter solenoid and all of the alternator connections.

Next, I recommend that you remove our alternator and have it bench tested at a shop, heck even Autozone will do this for you for free. This test ensures that the alternator internal diodes and rectifier are working properly as well as outputting the proper voltage. This test also removes the possibility that your cars wiring, battery and / or voltage regulator are causing your issue.

Now knowing your alternator functions correctly, test the alternator on the car, you need to excite the circuit by revving the engine above 2000 rpm. Turn on the headlights, stereo and heater blower to place a load on the electrical systems. Next measure the voltage at the Bat post on the back of the alternator or the battery connection at the starter solenoid. This should measure between 13.5 and 14.5 volts.

If the system reads only 12 V, basically battery voltage, then disconnect the plug at the voltage regulator. The plug is vertical with the following 4 wires in the connector
I - bottom goes to the dash indicator light circuit
A - This wire goes to the Bat post at the alternator. If the battery is connected, you should be able to measure 12 V here
S - Stator output from the alternator
F - Field - This is the field excitation circuit to the alternator.

Using a jumper wire with male connectors on both ends, place one end in the F terminal connector and the other end on the A connector. The
This effectively bypasses the voltage regulator and provides full excitation on the alternator. The voltage reading at the bat post should now read 15V. If it still reads only 12 V, then the wires to/from the alternator and the regulator are suspect. Perform this only as a quick test!

Using a multimeter, check the resistance of the A, S and F wires from the Voltage regulator plug back to their corresponding connections on the alternator.

I had the same problem with my Cougar earlier this year. Turned out that my voltage regulator was not energizing the alternator's field circuit which caused my issue.


Coach Jack
 

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Maybe a dumb idea, but perhaps you have a huge amp draw on the battery?
An easy way to see is when you disconnect the neg terminal (ignition OFF) and then putting it on again. If it Sparks then you have a draw somewhere.
 

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I would be going thru and checking all your battery cable connections ,,, both positives and negatives on block,body and frame ...
 
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