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Discussion Topic:
charging system
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Fred Hanks |
12-28-2010 @ 9:02 AM
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Member
Posts: 30
Joined: Aug 2010
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I was getting no charge showing on my amp gauge...had regulator checked out and is ok.. found bad gen. installed another gen and now I must rev engine to high rpm's to get a charge to show up on gauge..is this normal ????
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supereal |
12-28-2010 @ 1:05 PM
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Senior
Posts: 6819
Joined: Oct 2009
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Fred: To answer the question, we have to know what year vehicle you have, and whether it is a 2 or 3 brush generator, and did the system function properly before the problem arose? When you say "regulator", is it an actual 2 brush type on the firewall or the round cutout on the 3 brush generator? If it is a 2 brush type, it is likely the generator output is insufficient to cause the cutout relay to close. This can be due to a number of problems stemming from the condition of the generator itself, or can be caused by a poor generator ground, or a battery with a high resistance cell. Sometimes it is just a glazed or slack drive belt, or one poor connection.
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Fred Hanks |
12-28-2010 @ 2:24 PM
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Member
Posts: 30
Joined: Aug 2010
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It is a '51 Coupe & the gen is 2 brush w/ reg on inside fender panel lt. side.... I don't no how long it has been bad. Thanx, Fred
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alanwoodieman |
12-28-2010 @ 3:23 PM
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Senior
Posts: 868
Joined: Oct 2009
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sounds like the reg needs adjusting or replacing, I like to have the gen and reg set up by my generator rebuilder
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supereal |
12-28-2010 @ 7:18 PM
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Senior
Posts: 6819
Joined: Oct 2009
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Thanks for the info, Fred. I'm curious how the regulator was tested and pronounced OK. We often find an incorrect regulator on a vehicle, or one that has been "adjusted" by some trial and error. It is also possible that a perfectly good regulator doesn't work properly because it isn't grounded. Some regulators have a separate ground lug, while others depend on a metal ferrule in one of the rubber mounting feet to provide a ground, but failure to remove the paint or dirt, etc, to make a good body contact defeats the purpose. Same is true with the engine ground strap to the body, which sometimes is missing altogether. We do a lot of auto electric at our shop, and it is safe to say that poor grounds are the cause of the majority of problems. It takes some detective work with a good volt/ohmmeter to pin down these types of causes.
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Fred Hanks |
12-29-2010 @ 2:33 PM
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Member
Posts: 30
Joined: Aug 2010
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I am having another gen. rebuilt and I'll have the regulator mached to it..hope that solves all. Fred
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supereal |
12-29-2010 @ 3:10 PM
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Senior
Posts: 6819
Joined: Oct 2009
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Hope so, Fred. There are not many shops today that know what a generator is, or how to fix it. Turning a commutator and undercutting the mica has become a lost art. Today, we are dealing, more and more, with charging systems that use the ECM to regulate charging. Given some TLC, the generator/regulator set up certainly served well from '39 on into the 60's. As vehicles are loaded with accessories, I'm betting the 24 or48 volts will become the norm, as they have in military use.
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51f1 |
01-12-2011 @ 7:00 PM
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Senior
Posts: 573
Joined: Oct 2009
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Could it have the wrong diameter pulley on it?
Richard
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TomO |
01-13-2011 @ 7:38 AM
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Posts: 7256
Joined: Oct 2009
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Using an ammeter to determine if a generator and regulator are working properly is an exercise in futility. The ammeter will just show the amount of current flow and the direction of the flow. When a battery is at full charge, there will be very little current flow, no matter what the engine RPMs are. A sulfated battery will also cause little current flow in the circuit, because it cannot accept more of a charge. A volt meter connected across the battery will give you a better idea of the condition of the regulator and generator. With a 6Volt system, you should see about 7.2-7.6 Volts across the battery at 1500RPM with a generator and regulator that are working properly. Any reading out side of those specs will cause problems.
Tom
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