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Discussion Starter · #1 ·
I've been battling this one for a while now, I first thought it was just bad ground, my negative cable was corroded and rusty. I cleaned that up and realized it was a 6 gauge cable, and replaced it with a correct 4 gauge cable I had in a box of parts off our old truck. Made sure all the connections were clean, sanded them clean, and then tightened to snug.

Multimeter read 11volts on the battery while the car was running. I could pull the positive cable off the battery and the engine would still run, as long as I had all lights and heater fan off. If I even turned on my interior lights, the car would die.

So, I took the alternator in to Schucks, they told me it was bad. Spent $40 on a new one, brought it home and installed it. Same old 11volts when connected, and disconnected, dies with lights.

I think the voltage regulator was replaced recently before I bought the car. When I bought the car, it came with a parts bin, which had a voltage regulator in it in a voltage regulator box, and just by sheer observation, I assumed the one in the box was the old one, and the installed one was much newer.

Now I'm thinking Schucks lied to me, but I could be wrong. All my connections seem clean. Any ideas?

Thanks
-Matt
 

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I already told you to replace the voltage regulator for 11 bucks and get new cables or atleast a good set of terminals for another 11... read your last post on this same issue, I explained what happens to the cables. As per the regulator, moisture gets inside quite fast if not sealed right from the factory... especially by today's standards... my last regulator lasted a mere 8 months. Also you need to test amps, not volts. A bad voltage regulator will ruin your battery - if it already hasn't - by sending excess power.
 

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Ditto on the new cables, if you peeled off the insulation I bet you would find the cable to be green inside (corrosion). USUALLY, a bad regulator will allow too much current or none at all it sounds like you are not getting enough voltage. Before you go off and spend more money, as a test perhaps you can try running another ground ( heavey guage wire) parallel to the old cable and the same on the POS side and see if it helps...
 

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lemonshindig said:
to snug.

I could pull the positive cable off the battery and the engine would still run, as long as I had all lights and heater fan off. If I even turned on my interior lights, the car would die.
Never Ever Ever pull the cables off the battery with the car running. It is one sure way to blow the alternator.
 

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Discussion Starter · #5 ·
My uncle's always told me that's how to check your alternator. I've had others tell me that it hurts the charging system, but since I don't know how to test it any other way, that's the moethod I've stuck with up till now. Tell me how else I can check it, and i'll gladly do that. I have a multimeter.

The cables are new. They aren't corroded, trust me. Now the alternator is new as well. I'll see if the old voltage regulator changes anything. If not, then I'll try a new one.

Now you say I need to measure amps, not voltage - That's what I thought. I'm no electricity buff though, so everyone I talked to said I need to check voltage, and I trusted them. I've been told that while the engine's running, the voltage at the battery should be 13-14 volts, which makes since, to charge a 12 volt battery.

When I try to measure amps, the multimeter reads 0. I guess I really just don't know how to work the thing.

Thanks
-Matt
 

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If you tested for amps right and you get zero its the voltage regulator. Same thing happened to me. It looked "good" on the outside, but was fried in the inside. I can even post a pic for you, I saved it somewhere because I was pissed at the short life it had and the poor construction... I was going to raise hell somewhere (I didnt know where) but now I'm over it. Anyway, check to see if the regulator gets hot... thats one way to check if there is a short inside... also whoever tested your alternator might have a regulator test.

Also, did your car parts shop test the alternator while in the car? If so and they said it was bad maybe they got a bad reading because of the regulator... if not then maybe the regulator screwed your alternator AND battery now as well.
 

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I'm curious---- considering the trouble you have had with the voltage regulator, is the regulator in question an electro-mechanical regulator (reproduction regulator from a Mustang catalog), or is it an electronic regulator( the kind you get at parts stores as a replacement for the originals)?
When I bought my F/B I noticed the lights got dimmer when idling. Didn't like that, heard about trouble with reproduction VR's, so I bought a replacement (electronic) at Advance Auto for less than $15.00. That was over three years ago---not a problem since!!!
Granted, the regulator doesn't LOOK like the original (smaller, thinner and lower), but it WORKS!!! I've never had anyone look at the car and say "Wow, nice car, but too bad you have the wrong regulator in it". I have also read that there are reproduction regulator cases that fit over the electronic regulators so you can't tell the car has a modern, electronic regulator, the same idea as the battery covers. IMHO it's just one of the upgrades that you have to make to drive a vintage car in today's world.
Jay67fast
 

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Discussion Starter · #8 ·
Turns out the alternator was infact the problem, but when i installed the new one, I didn't get the belt tight. Tightened it up and what do you know, 13volts at idle and 14colts under load. I'll be sure and check the amperage, too, but I think it's working.

Thanks a lot
-Matt
 
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