charging system help!!

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1968dartman

1968dartman

life is getting better!!
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I need help with my charging system in my 68 dart. It has had the charging and ingition systems upgraded to the newer electronic . I recently bought the car and put a complete new wiring harness from Year One with the upgrades already in the harness. I canot get the car to stop overcharging like crazy. I have put two different alternaters, 4 voltage regulators all with the same result . I was told that perhaps it was a ground problem so I put two new grounds on the car. Still the same result. I am wondering if the original ammeter in the dash might be part of my problem as I am at my wits end!!
 
Sometimes the altenator itself requires a ground, did you go from a one field alt to a two field? I run a ground from the battery to the block and the frame and then a ground from the engine to the body.........
 
I have done that already and it did not seem to help. If I put a new regulator on the car it works fine for about 30-45 seconds then goes crazy again.
 
OK, first WHAT kind of alternator / regulator you using, I.E. the 70/ later Mopar, or Delco/ Ford, etc?

Overcharging on (such as) the 70/later Mopar system can be caused be either or BOTH a ground problem or an ignition voltage problem

FIRST, engine OFF, key in RUN, put one probe on your battery positive, the other probe on your IGN terminal supplying the regulator and ignition. What you are measuring here is VOLTAGE DROP from the battery to the regulator. You want to see LESS THAN 1/2 volt, the lower the better, zero would be great.

Next, start the engine, and make these tests with the battery up and normalized, first with all accessories off, and again with heater, lights on

Put one probe directly onto the battery negative post, the other directly onto the regulator case. Make sure you "stab" through the paint, chrome, etc. You are wanting to see a very low reading NOT more than .2 (two TENTHS) of a volt. More means you need to look for ground problems

Now check the hot side. Put one probe directly onto the battery positive post, the other on your IGN/ regulator supply from the key. Once again the lower the better, zero volts would be perfect, and over .2V is too much.

If all this checks out, you may have a battery problem.
 
I am running a two wire mopar alternator and a mopar elctronic voltage regulator
 
where will I find the ignition terminal? Do you mean on the ballast resistor?
 
1968dartman said:
where will I find the ignition terminal? Do you mean on the ballast resistor?
Click to expand...

Yes, the IGN wire from the key, I.E. "ignition run", or "ign1" or the traditional "dark blue" is hot in run, supplies the ignition system (key side of the ballast), the alternator field, and the regulator IGN terminal
 
OK- all tests completed . On the first test with out motor running there was a 1/2 volt difference. On the second test the reading was 0 and on the third test it was 0.01. Sounds like battery perhaps?
 
Boy do I have a story to tell! It ended up being my altenator after all. When I was changing from one altenator to the other we were changing one brush holder because it was missing on the other alternator. So I decided to get the spare alternator checked and I put the brush holder on it and went and had it tested. It was missing an insulator on the brush holder we were changing :eek:ops:which ended up being my problem from the get go! Thanks for all your help everyone with this silly problem! We are going cruising tonight and will not have to worry about getting home before dark.
 
You're lucky the grounded brush was on the regulator wire. If it had been on the blue, it would have burnt up some harness and maybe a few other things.
 
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