Charging issue '70 Swinger

This is NOT normal, but it's difficult to imagine just what might be wrong.

You MIGHT have serious issues with the 'ol bulkhead connector, OR you might have an alternator that is not capable of putting out enough amperage,

Here's how I see some of the possibilities, and you might have multiple problems

FIRST how did you measure this voltage at the battery? It SOUNDS like you measured it with engine running? If so, it should be charging much closer to 14 RUNNING with the battery "normalized" and all loads (lights, heater, etc) off

Possibilities:

Might even be a battery problem

Resistance in the charging path from the alternator to the battery. This goes through the BULKHEAD CONNECTOR and is the no1 suspect. Read this:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

and note their simplified diagram. It outlines just how this circuit is put together.

Might be resistance in the field circuit not allowing the alternator to develop full output when needed, OR might just be a defective alternator Just one example might be a couple of bad diodes which can turn a 60A alternator into less than a 20A alternator.

In your case, this seems so screwed up, read through your shop manual in the electrics section concerning testing the alternator. If you don't have one, download one here:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download

IN your case the 72 manual is as good as any for this purpose.

Some things to check:

Check the voltage drop in the circuit path from the battery--fuse link--bulkhead connector--ignition switch connector--through the switch--back out the switch connector--back out the bulkhead--to the alternator field.

TO DO THIS, turn the key to "run", engine OFF. Get a probe or clip lead so that you can probe the BLUE wire (not the green) at the alternator field. Put one meter probe directly on the battery positive post, and the other on the blue wire on the alternator, and you are measuring "voltage drop" so you are hoping for a very low reading. Zero would be perfect, you hope to see NOT OVER .2-.3V, that's three TENTHS of a volt. Anything over about 1/2volt means you have a poor connection somewhere.

IF that checks out, start the car, all loads off (lights, heater, radio, off) and run at an RPM to simulate "low cruise" (fast idle cam is OK) until the battery "normalizes" IE ammeter CENTERED.

IF it just won't do that, ignore, and check the battery after starting and running for 5 minutes. You would LIKE to see very close to 14V. Turn on the headlights, heater, and recheck. IF this voltage drops dramatically at the battery, move the meter probe over to the alternator output stud and recheck, loads on, loads off.

This voltage should NOT be much higher than battery voltage. If it is, this shows that you have a bad connection in the circuit path from the alternator to the battery. Refer to the Mad Electrical diagram at the link I posted to see how this works.

If the voltage between the battery and alternator output stud are NOT quite different, IE about a volt, maybe 2, then you MAY have an alternator that is not capable of enough output.

To "quick check" this, use clip leads, and disconnect the alternator field connections. Clip one of the two field connectors on the alternator to GROUND, and clip the other to the battery.

Start the engine, and carefully bring up the RPM. The battery voltage should start to climb, up over 14, but do NOT let it get over 15--15.5. You can turn on lights heater, and bring up RPM again, slowly, and recheck. Once again, you should be able to get the voltage up over 14.

IF NOT, recheck the difference in voltage between the battery and the output stud of the alternator. IF these two voltages are within say, 2 volts or less, then you have some problem in the alternator.

This nonsense of dripping resin from electronic boxes has been with us for some time now. GENERALLY it either means the box has some problem, or that it's a cheap Chineseo copy that simply is not as good as OEM.

Once again---you may have multiple problems here. You may find yourself seeking shop help.