Battery not charging...alternator/electrical help please!

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Joined
Aug 9, 2010
Messages
131
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Location
Columbia, Mo.
My Car
'72 Fastback (Mach Badging)
'06 Coupe (Mach Tribute)
Hey Guys,

While traveling to a show a couple weeks ago, my radio started acting funny. It would nearly go off then back on...then off and back on...once I got to the show, 80 miles from home, I drove to the lot boss and while talking my pony died, and would not turn over...The lot boss jumped me and I made it to the parking area when it promptly died again. My guess at the time was bad alternator since I had a new battery already. I was able to get it going and made it home. whew!

Anyway, I ordered a new alternator, regulartor and cabling. Alternator arrived first. When I installed and took out for test run, still not charging. When my backordered cable arrived, it was for the instrumentation version, and mine does not have that. I finally got the regulator and started voltage testing with both old and new regulator. To make this long story shorter, it is still not charging battery...I am seeing about 12.22VDC when at idle. I would think it needs to be at least 13.5 or more to charge.

WHat I need to know is what I should be reading at the regulator when at idle on the two center pins. The new regulator has the outside pins as ground and linked together.

If anybody has any ideas of what I can test or what else may be my problem, I am open for suggestions...

Thanks...JB

 
unplug the regulator, jump the 1st and 3rd terminals.....that bypasses the regulator and that should make the alternator charge MAX.

On a ford, where the wires snap on to the alternator...the boots should be color coded to the insulators on the Alt.

There should also be a fuseable link hooked to the solenoid...see if it has burned out....you can usually feel the wire and tell it has burned.

 
Don, Thanks for the reply. It seems that my new regulator I got from CJ's is a bit different than the Wells unit that was in the car. On the new one, pins 1 and 4 are externally shorted (as shown in picture) and seems that pin 2 is not connected to anything. My old one has some different readings also as shown in pics.

As to the fusable link, it appears ok down to the place it goes into the harness but I don't know what it is supposed to read or when the other end runs to...

I suppose I will try to order another harness and try it.


Here is what my alternator / regulator harness looks like now where it plugs into the regulator. I think it may have been changed and "modified" by previous owners so don't know if colors are right or what needs to go to what actually...

You can see the yellow fused link and where it runs into the other harness.

IMG-20120923-01130.jpg

IMG-20120923-01129.jpg

IMG-20120923-01131.jpg

IMG-20120923-01132.jpg

IMG-20120923-01133.jpg

IMG-20120923-01134.jpg

IMG-20120923-01135.jpg

 
Last edited by a moderator:
I had the same experience, replaced battery, alternator and voltage regulator, still not charging. I found some problems with alternator harness (performed temp repair until I work with MidLife on correct alternator harness for my car), but still not charging. Some research revealed the problem is the green wire with red stripe (the one you are holding in your hand in picture). It should have some voltage providing reference signal that is used to determine if the charging system should charge the battery. I was getting zero volts so knew I had a short somewhere. I told my son the problem is the green wire with red stripe and he found the problem in 4.5 minutes -- it was in the harness running along the core support. A quick repair and now getting 14.5 volts when engine is running.

 
Gentlemen,

Although I respect the heck out of folks that try to stay as original as they can, this is another example of when getting newer technology pays off. I recommend a one-wire, high amp, internally regulated alternator so you never have to mess with stuff like this again.

The same thing happened to me 7-8 years ago and I vowed to never let it happen again.

Ken

 
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