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New electronic Voltage regulators getting warm, with Engine not turned on yet...
- Thread starter reamer
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serial car restorer
Yes, I'll restore almost anything...
Please clarify - is this the charging system regulator, or the regulator for the gauges?
Broncobowsher
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No, it's bad.
Key off, there should not be any electrical load. You have heat, that is wattage, that is sucking the battery dead.
Now is it a bad regulator, or is it bad wiring keeping the regulator powered up (think key on) when it should be off. That will take a little deeper investigating.
For now, keep the battery disconnected when not activly working on it. Or you will run the battery flat and probably kill it.
Key off, there should not be any electrical load. You have heat, that is wattage, that is sucking the battery dead.
Now is it a bad regulator, or is it bad wiring keeping the regulator powered up (think key on) when it should be off. That will take a little deeper investigating.
For now, keep the battery disconnected when not activly working on it. Or you will run the battery flat and probably kill it.
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Stock wiring harness, or aftermarket?
In a stock, or Painless wiring harness, the green with red stripe wire at the regulator should have zero voltage on it when the key is in the OFF position. And 12 V when the key is in the ON position.
But you said “the engine not running” instead. Does that mean the key was on? If so, then it’s normal and it is exactly why you never leave the key on.
If the key was off, and the engine was off, then as was mentioned previously, something is amiss.
In a stock, or Painless wiring harness, the green with red stripe wire at the regulator should have zero voltage on it when the key is in the OFF position. And 12 V when the key is in the ON position.
But you said “the engine not running” instead. Does that mean the key was on? If so, then it’s normal and it is exactly why you never leave the key on.
If the key was off, and the engine was off, then as was mentioned previously, something is amiss.
OP
OP
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Soo, I did some measuring, Key off (key out of ignition) unplugged the harness from the voltage regulator, It's the yellow wire at the voltage regulator supplying 12V to the regulator....
For fun I dis-connected the Alternator and there is 12v in the large wire. Is that normal???
With Alt completely disconnected, there is still 12 in the yellow wire (key out of ignition)
For fun I dis-connected the Alternator and there is 12v in the large wire. Is that normal???
With Alt completely disconnected, there is still 12 in the yellow wire (key out of ignition)
Last edited:
Broncobowsher
Total hack
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The large wire on the alternator is a direct feed to the battery. Having 12V there is correct.
The regulator has 3 wires. I don't remember wiring colors, just function.
One is switched power. Should only be hot in run. This tells the charging system to work.
Another is always 12V. It goes straight to the battery. This looks at the battery voltage without the voltage drop of the rest of the wiring system. This will always have 12V to it.
Third wire is the field wire. This is a variable voltage to the field terminal on the alternator. It is the throttle for the charging system. No voltage, no charge. Full system voltage, max alternator output. You get this after a start as the battery is recharged. Then it tapers down to throttle back the alternator output to match loads.
The regulator has 3 wires. I don't remember wiring colors, just function.
One is switched power. Should only be hot in run. This tells the charging system to work.
Another is always 12V. It goes straight to the battery. This looks at the battery voltage without the voltage drop of the rest of the wiring system. This will always have 12V to it.
Third wire is the field wire. This is a variable voltage to the field terminal on the alternator. It is the throttle for the charging system. No voltage, no charge. Full system voltage, max alternator output. You get this after a start as the battery is recharged. Then it tapers down to throttle back the alternator output to match loads.
serial car restorer
Yes, I'll restore almost anything...
Any other recent changes or replacements lately? Like a new ignition switch?
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Test the ignition switch. Did you get a new connector and pigtail with it? Check that especially.
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As already mentioned, this is correct.
Also, correct.
Yep, correct. The yellow wire at the ignition switch and the yellow wire at the voltage regulator are always hot.
OP
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Broncobowsher
Total hack
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FYI, you can fry a voltage regulator in about half a millisecond if you power it up without being grounded.
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Good point.
You can connect or disconnect a regulator from its plug even with the battery connected. But you can’t ever take a chance of connecting the regulator to the system before it’s mounted to the body and before the little ground wire from the Alternator is attached.
There should be a small black ground wire between the ground studs on the Alternator and the mounting bolts of the regulator.
If the original harness is intact, then there is a small metal ring sticking out of the rubber molded strain relief with all the wires going to on the back of the alternator.
That tab should be under one of the nutted grounding studs on the alternator.
Then there should be a little wire running from there up to the regulator
If that’s not there any longer, you should probably create one.
Making sure not to fry another regulator.
That’s not to say this is your fault. It’s entirely all too likely that the regulator was bad right out of the box. No matter what brand anymore, no matter what you pay. Far too many parts are bad in the box.
You can connect or disconnect a regulator from its plug even with the battery connected. But you can’t ever take a chance of connecting the regulator to the system before it’s mounted to the body and before the little ground wire from the Alternator is attached.
There should be a small black ground wire between the ground studs on the Alternator and the mounting bolts of the regulator.
If the original harness is intact, then there is a small metal ring sticking out of the rubber molded strain relief with all the wires going to on the back of the alternator.
That tab should be under one of the nutted grounding studs on the alternator.
Then there should be a little wire running from there up to the regulator
If that’s not there any longer, you should probably create one.
Making sure not to fry another regulator.
That’s not to say this is your fault. It’s entirely all too likely that the regulator was bad right out of the box. No matter what brand anymore, no matter what you pay. Far too many parts are bad in the box.
