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Discussion Starter · #1 ·
Hey guys, I'm a newbie to these forums and would like to say that there are some great posts. I have a 1972 El Camino that has the gen. idiot light on constantly. It has been this way ever since my alternator shorted one night and fried my fusible link at the starter. I have replaced the alternator, the starter/selenoid was replaced about 3 weeks before that, and i ran new wire to from the alternator to the voltage regulator(which was also replaced). When i stick a volt meter to the battery, i get around 12 volts, usually a little under. My only question is where do i look for the problem. It is a 350 and has an hei dist. The only thing i could think might be causing a problem is i used the 12v pink wire from the ignition to power the hei, but ive read that that is the best way to do it. Thanks in advance.
 

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Troubleshooting the GEN light problem.
1, Remove the plug from the regulator.
2, Turn the ignition key to the ON position.
3, Measure the regulator connector brown wire to a good ground. You should have around 12 volts.
4, If (3) is around 12 volts, switch the key to OFF.
5, Install the regulator connector.
6, Remove the plug from the alternator.
7, Turn the ignition key to the ON position.
8, Measure the alternator connector blue wire to a good ground. You should have around 12 volts.
9, If (8) is around 12 volts, switch the key to OFF.
10, Install the alternator connector and start the engine.
11, Again measure the alternator connector blue wire to a good ground. You should have around 12+ volts.
Post back the results.
 

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I had the exact same thing happen to my 70 El Camino. It turned out that the new alternator was bad. Bring it by Autozone and they can check it for free......
 

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Discussion Starter · #4 ·
Sorry for the delay, I haven't had time to check it lately due to work and school, but I did have the alternator checked at Advance Auto Parts twice and it checked good. Ill post the results hopefully tonight on the test.
 

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Discussion Starter · #5 ·
alrighty, here goes:
Battery=12.1v
Brown connector to ground=11.8v
ALternator(engine off)=11.4v
Alternator(engine running)=flucuates and goes down from 7.4v.

My diagnosis is that it is the alternator, but everytime it has been tested, it checks out, and they wont swap it since it checks. Thanks for the past and future help guys!
 

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If the alternator tests OK then look at the regulator.

First off. When you put the regulator down in front of you with the terminals facing you the numbering should go F, 2, 3, 4 from left to right.

The wire going to the #2 terminal at the regulator should go up to a few volts once the car is started. This wire turns on the regulator and the regulator requires 1.5 to 3.2 volts to energize it. If the voltage is higher than that, it should be working.

When the regulator engages, the wire on terminal 4 should go to full or battery voltage. That's the wire the light goes to.

The wire on terminal 3 should have battery voltage on it at all times.

When off and the wires connected, check for continuity between regulator terminals F and 4. Should be a short.

When running, jumper the F terminal and the big power lug together on the alternator. This should easily produce voltages of 16 or 17 volts at idle or with a slight rev of the engine. Make sure anything electronic is off when doing this, such as stereo equipment. I can't remeber the wire colours, so just follow the F terminal from the regulator.

When you disconnect the regulator, the light should go out.

If you pull the regulator cover, you should see 2 coil and contact assemblies. 1 will have a single contact. This is the energize coil. It should be closed whenever the car is running. The other coil/contact assembly will have 2 contacts with the middle being double sided. This is the regulating coil. It should bounce between the contact sets while the car is running.

That's all I have. Let us know what you find.

Peter
 

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Discussion Starter · #7 ·
Sorry it took so long again, been doing bodywork(thats in my next post), but apparently it was the light bulb in the charging circuit, because it glowed dimly the whole time, well i replaced it and it glows bright as ever now...weird though cause the dull charging light would glow bright in the oil light place. Oh well, guess i have electrical gnomes. Thanks for the help.
 
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