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Roger Frazee

Voltage Regulator Problem

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Today I replaced the aftermarket solid state voltage regulator on my 1966 Corvair, with a new OEM Delco Remy unit.  The new regulator allowing the alternator to overcharge.  I am reading 17.2 volts when the engine is running.  Also, the alternator light stays on all the time.  The light gets brighter as the engine RPMs increase.

 

The regulator is isolated from the body with rubber grommets, as it should be.  I experimented with grounding the regulator case and, it caused the alternator to growl.

 

Any advice on my regulator issue is much appreciated.

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That new Delco unit must be defective, especially if your old solid state unit was working fine for you.  The regulator should be keeping the voltage at the right level if it’s set up properly at the factory.

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Do you have a copy of the shop manual? In it you will see the regulator case should be grounded. Grommets are just for shake and vibration reasons.

 

We are discussing a stock system, right? I have to ask because most all the charging questions on other forums are from installing "one wire" alternators and not following directions ( or directions that are right, hey, I saw it on the internet, it must be the right way....🤪).

 

New regulator or used regulator or new to you but old stock regulator? 

 

Why were you replacing the solid state unit? 

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Yes if your regulator is rubber shock mounted then you must ground it . Delco regulators usually have a predrilled hole on the metal base by the single mounting ear specifically for a ground connection. I also ask why you were making the change to start? 

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Thanks Frank and Certjeff1.  I was doing some digging  last night and found statements that confirm your advice.  I was thinking the rubber grommets were there to isolate the regulator from ground but obviously this is not the case.  I will ground the VR today.  I'm confident that will solve the problem.

 

The reason I'm changing the VR is because the solid state unit stopped giving me a warning light when I turned the key on.  On a Corviar, the warning light is critical as this is the only indication you will have if the fan belt comes off.

 

 

Edited by Roger Frazee (see edit history)

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Also check the red wire in the regulator plug. This is your battery sense and must have battery voltage at all times.

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OK.  I confirmed that the red wire has voltage and I grounded the regulator to the body.  Now, I get 17.8 volts when the engine is idling.  Also, the alternator whines when the engine is at idle speed and the generator light is on.  

 

Above idle speed, I am reading 14.4 volts, the generator light goes out and the alternator stops whining.  

 

Just to make sure I had a good ground, I jumpered a wire from the regulator frame to the alternator ground lug.  No change.

 

Is there an adjustment within the regulator that needs to be tweaked, or do I have a bad regulator, as TerryB suggested?

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At some point I would put the solid state unit back in and take voltage readings with it installed.  Usually voltage goes up when engine speed increases so yours goin down is strange as is the warning light being on at idle.  It sounds like the new regulator starts working as it should when the engine speeds up.  What happens if you put the parking lights on when the engine is idling ?  Does this make the new regulator change voltage?  What is the part number of the new regulator?

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13 minutes ago, TerryB said:

At some point I would put the solid state unit back in and take voltage readings with it installed.  Usually voltage goes up when engine speed increases so yours goin down is strange as is the warning light being on at idle.  It sounds like the new regulator starts working as it should when the engine speeds up.  What happens if you put the parking lights on when the engine is idling ?  Does this make the new regulator change voltage?  What is the part number of the new regulator?

 

I agree that, for some reason, the regulator does not start working until the RPMs increase.  It must be set to kick in at a voltage greater than 17.8, which is why I was wondering if there was an adjustment in the regulator.  I know the old timers used to adjust the spring tension on the relays to make them work properly.

 

Anyway, I've got a replacement on order.  Hopefully it will work better.  I'm too stubborn to go back to a solid state regulator if I don't have too.  

 

HERE is the link to the part that is giving me problems.

 

Here is the link to the replacement part I ordered today.

 

 

 

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The spring tension is supposed to control the regulator as you say and some seem to fiddle with it and have some success, usually in generator applications.  I’ve never had to do that.  You may want to confirm your four wires on the plug go to the correct locations on your alternator as shown in the shop manual wiring and the connections in the plug are clean and making good contact.

 

Good luck my friend!

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My first check would be if the DMM (or whatever meter you are using) is reading right. Always good to confirm test equipment. I've seen weak batteries in DMMs give wacko readings. Cause hair pulling experiences, DAMHIK.😊  Most recent hair puller one was a faulty lead on a Multimeter (analog type). 

 

I've had the internal regulator Delco alternators not charge until the rpms are raised above 1000 or so. Never had an external one do it. Yet....

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Yes, it is nice for the GEN FAN light to come on before the TEMP PRESS light lights on a Corvair!  The generators on the earlies  have been know to "motor" when the belt is thrown off, not lighting the GEN FAN light. 😲

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Thanks Frank.  I see that there is an air-cooled seminar at the Annual Meeting in Philly.  Will you be there?

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17 plus volts sounds to me that you are in a full field situation and that would also be why you hear the alternator whine. If you put an ammeter in the circuit you will probably see 37 to 55 amps. When an alternator is producing amperage it creates a whine. The more amps the louder the whine. When the system falls into the normal voltage range you will probably see the amperage go down as well. And the alternator quiets down. It is very common with mechanical regulators to see the voltage rise slightly as you take the engine up from idle. Not the other way around. At this point because you have your light function back and the voltage does drop into the normal range I would say your wiring is fine. I would take the regulator off and test it with an alternator on an alternator test bench. If you get the same readings on the test bench then yes you have a bad regulator if you get good readings then you have something wrong in your system and it is affecting this regulator differently than the other one.

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Funny, I was thinking the wiring might not be ok, that there is a dirty or loose connection somewhere.  Isn’t the gen light connection critical for the regulator to work properly so if the connection is poor would that make the alternator act strange.  Also, good battery connections are important at the alternator and where the alternator output goes to the battery.

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http://www.delcoremyhistory.com/Service Manuals/introdelcotron-1962.htm

 

Make sure battery cables are good, and that chassis, engine, and battery are all grounded together. I don't remember exactly how that was done on a Corvair.

 

I am a bit suspicious of the alternator diodes at this point. If testing the regulator doesn't get the desired result, IMHO either test the alternator with an oscilloscope, or take it off and take it to someone who can test for bad diodes (with an oscilloscope) using a test bench.

 

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Dirty or loose connections create high resistance and thus poor, low or intermittent charging voltage. Not an excessive reading. The light simply turns on the alternator. If you have a bad bulb the alternator will not turn on. As far as loose or poor connections in the light circuit causing charging problems this will not happen. If he had said that there was no voltage in the red wire at the regulator then that could cause voltage excessive readings as that is the regulator voltage sensing wire. And if the regulator reads no voltage in that wire it thinks the battery is dead and tells the alternator to produce everything it has. But changing engine rpms will not put the alternator into normal charging range. It will be high until you fix that wiring problem. Yes bad connections at the alternator can cause output problems. Always poor or low readings. You will see a normal 14v reading at the alternator output post and a much lower reading at the battery. 

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I was thinking the sense line to the battery junction might be poor connection so that the alternator gives its all.  With a little more engine speed some engine motion or vibration might improve the connections.  Certainly many avenues to explore!

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16 hours ago, Frank DuVal said:

 

I've had the internal regulator Delco alternators not charge until the rpms are raised above 1000 or so. Never had an external one do it. Yet....

 

This is common one wire alternators.

It takes a little goose to excite the rectifier.

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3 hours ago, Bloo said:

I don't remember exactly how that was done on a Corvair.

 

On lates, (65 to 69), the negative battery terminal has a large and small wire exiting. The small wire connects to the body (washer head sheet metal screw right at the battery area and the large wire connects to a head bolt, which also holds the rear alternator bracket to the head (3/8-16 washer head bolt).

 

12 hours ago, Roger Frazee said:

I see that there is an air-cooled seminar at the Annual Meeting in Philly.  Will you be there?

 

This seminar is not on the schedule I printed this morning. I could not get it to print right from the webpage, had to save it as a pdf and reopen it. Aren't computers wonderful????🙄

I would go to it.

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Roger  I se you have  a 17 Overland . I am doing a 1916 model 75 Would like to get with you at Philly Kings32

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Lings32,  Always glad to meet another Overland owner,  There will be a get-together of discussion forum members  in the lunch area on Friday, during the lunch break.  Maybe we could meet up then.

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