Classic/Antique Car Repair: 1967polara charging system, 1967 dodge polara, ballast resistor

Question
My freind has two 1967 Dodge polara's. they both have charging system problems. he has a new alt. and he changed the reg. from a point type to a electronic type. when I tested at the alt. got same as battery,11.3 volts. no 13.5-14 volts. the alt has 2 spade connectors and the reg has one wire for the alt. that is suppose to go to the field side of the alt. the other polara has the original setup.these cars are in good shape, no scabbed together wiring or add ons. can you walk me through the system used on these dodges? Thanks

Answer
Sure!  The alternator will not charge unless there is battery voltage on the field terminal - that is the smaller of the two wires going to the alternator, and it is probably dark green.  It comes from the field terminal of the regulator.   The regulator must be securely grounded, and the other wire on the regulator comes from the ignition system - it is a dark blue wire, which is connected to the 12 volt side of the ballast resistor.

The second wire on the alternator is much heavier, and is black. It goes to the bulkhead connector on the firewall, probably to pin "P", which is the second pin down from the top on the center section of the connector, on the left side of the connector.  That wire goes to the ammeter, then back to the battery on the heavy red wire that comes back through the bulkhead on pin Z of the bulkhead connector, which is the lower left one on the left section of the bulkhead connectors.

If there is battery voltage on the field terminal of the alternator, but only 11.3 volts on the other wire from the alternator with the engine running (and the belt is tight), the alternator is a bad one.  If there is NOT 12 volts on the field terminal, investigate the regulator.  There should be battery voltage on the ignition terminal when the key is on, and there should be 12 volts (more or less) on the field terminal also.   If there isn't and the regulator is well grounded, the regulator is bad, or the wire on the field terminal is shorted to ground.

If all is OK with the field connections, and you do see battery voltage on the field terminal of the alternator, you should also see 14.5 volts or more on the output of the alternator - if you don't, the alternator is bad. If you see the 14.5 volts or more at the alternator, but not on the battery itself, the problem is in the wiring from the alternator to the battery.

90% of these problems are due to poor connections at the bulkhead connectors - you may have to unplug them and clean all the metal contact.  Most of the remaining problems are in the ammeter or the connections to it.

Some Polaras did not have ammeters - in that case, just trace the connection from the alternator output (the black wire) back to the battery - I'm not exactly sure how it will be routed.  

But, from your symptoms, your problem is in the connection from the field terminal of the regulator to the alternator, or from the ballast resistor to the regulator, or possibly in the grounding of the regulator.

Dick