Ammeter Bypass / Charging Question

live4theking

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Sunday night my daughter noticed that my volt gauge in the 68 NYer bounced around some on the way home from the grandparents. When we got home I put my meter on the battery and it was getting 14.8 volts.

Yesterday I was going to drive it to work when about 2 miles from home I noticed the gauge bounce radically, for instance from 10 - 16 volts, I don't know exactly. This is with one of FURYGT's regulators. I turned around and took it home. When I got last night I put another one of FURYGT's regulators on it. At first idling in the driveway I got 14.5. I went for a 20 minute drive to Wal-Mart and checked it there and I was at about 14.7.

Having yet another of FURYGT's regulators that was brand new I put it on this morning and drove it to work, 16 miles - 25 minutes. Almost watching the gauge more than the road, yikes... There was some movement in the gauge, but I saw no radical movement. Pulled it into the shop and put meter on it right away. This brand new regulator is putting out 14.9 volts.

This morning I pulled and cleaned battery terminals (small amount of corrosion), scuffed up the firewall where the regulator mounts, and cleaned the one wire that connects to the regulator (the other plugs on).

Does doing the ammeter bypass cause you to see a higher charging voltage at the battery? Is it somehow not allowing the voltage regulator to do it's job? Is there something else I should be looking at?

I honestly don't know how long it has been putting out this high of a charge. If my daughter had seen it bounce on our way home Sunday night I may not have noticed it.

I'm considering buying a regulator for a local parts store to see what it does. Try a different brand. It seems strange though I've gotten basically the same results from 3 regulators - hence why I'm questioning the bypass.

We're supposed to leave for Carlisle Thursday evening.
 

FURYGT

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I spoke with John and he is going to have the battery and alternator tested. I suspect it's the battery on it's way out as it is around 6 years old and may not be holding a full charge.
 

cbarge

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When I tested the battery it showed to be just barely in the good range. I'll be getting a new battery.

Mind boggling because it starts the car just fine.
It can have a bad cell or sulfated plates or low on water/acid. At 6 years old it may start the car but for how long is limited.
It is probably not taking a charge hence the regulator pumping out higher than normal voltage.
One proper load test on the battery I bet it falls flat on its face.
Remember, all cars--even new cars-run on the battery. The alternator and other related items simply keep the battery charged.
 

Gerald Morris

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Check the cells, if any are below FACTORY SPECIFIED levels, remedy with distilled water, or better yet, a solution of epsom salts and distilled water. The magnesium sulfate in solution drives the plumbic sulfate BACK into solution somewhat, and at any rate, adds fresh sulfate ions to the electrolyte. Unfortunately, after 6 years, the SHAPE of the electrodes often changes in ways apt to short circuit, even with the best chemistry. New batteries aren't that expensive, yet....
 

live4theking

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Check the cells, if any are below FACTORY SPECIFIED levels, remedy with distilled water, or better yet, a solution of epsom salts and distilled water. The magnesium sulfate in solution drives the plumbic sulfate BACK into solution somewhat, and at any rate, adds fresh sulfate ions to the electrolyte. Unfortunately, after 6 years, the SHAPE of the electrodes often changes in ways apt to short circuit, even with the best chemistry. New batteries aren't that expensive, yet....
Fortunately you are correct. The new battery is setting me back about $130. I'll have it this afternoon for the drive home.
 

Gerald Morris

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Fortunately you are correct. The new battery is setting me back about $130. I'll have it this afternoon for the drive home.
Deo gratias! I copped a nice Type 27 from Sprawlmart for about that price last January. Type 24s will crank a Mopar big block OK, but a 27 does it more smartly. Sometimes, that matters. I use the modern Denso type starters when I can too.
 

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For future reference, Interstate still makes black batteries for the OEMs it supplies. Toyota, Hyundai, Lexus, etc.
 

live4theking

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Update. The new battery didn't change anything. It's still putting out 14.8 or so.

After work I went to see two guys that rebuild starters, alternators, and know charging systems. They bench tested 2 of the 3 regulators twice from FURYGT on one set up they were 14.2 on the other 14.3. Nothing wrong with them.

They measured the voltage at the battery, checked wiring and took some other readings across the system. Readings were high, but consistent.

He told me running it with the high input may shorten the life of the battery, but other than that it will be fine.

They loaned me an alternator as a spare and to use for testing to see if it changes anything. I may try swapping it tomorrow at lunch to see if it changes anything.
 

Gerald Morris

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You MAY try an adjustable regulator! They can be had, either old school, or a few modern, solid state sorts. The latter might be for squarebacks only though. OR, if you feel bold, a big power pot might avail with the solid state one from our peer from the Forum. Better yet, cop another solid state reg, crack it, and use that for such an experiment. You might burn one up after all. Also, see if something in the field of your current alternator has shorted, drawing full current to the field. What you describe suggests this possibility. I suspect the alternator or the reg will burn out before the battery, given what you're telling us.
 

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What is the voltage at other points in the system? The sense wire for the regulator is not at the battery. If the regulators test ok then wherever they are sensing voltage it's going to be 14.2. Usually one sees a drop in voltage in other places than the sense wire of course, to see a voltage increase is peculiar.
 

cbarge

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Was the new battery fully charged when you did the checking? Or just "new off of the shelf"?
AT my previous employer, we ALWAYS fully charged the new freshly installed batteries before the car gets picked up.
 

cbarge

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John, When reading 14.2 are you running EVERYTHING on?? All lights,hi beams,hazard flashers,wipers,blower motor, in DRIVE ??
It should drop and come back up.
With NOTHING on,14.2 seems normal at idle in PARK.
 

live4theking

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John, When reading 14.2 are you running EVERYTHING on?? All lights,hi beams,hazard flashers,wipers,blower motor, in DRIVE ??
It should drop and come back up.
With NOTHING on,14.2 seems normal at idle in PARK.
CBarge - 14.2 was the reading the regulators were giving when being bench tested.

At lunch I did a continuity check of the grounds. From the negative of the battery to negative ground on the engine, alternator, firewall ground, intake side of firewall ground, and the bracket for the regulator all were nearly zero. Then I swapped the "loaner" alternator on. At a fast idle it was putting out about 14.6 to 14.7. This is a a reduction of 0.2 to 0.3 volts. Once I kicked it down off of the fast idle it was down to 14.3 to 14.4.

This leads me to believe that I have an over achiever for an alternator. It's going to ride in the trunk as a spare and will be serviced after Carlisle.
 

Gerald Morris

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CBarge - 14.2 was the reading the regulators were giving when being bench tested.

At lunch I did a continuity check of the grounds. From the negative of the battery to negative ground on the engine, alternator, firewall ground, intake side of firewall ground, and the bracket for the regulator all were nearly zero. Then I swapped the "loaner" alternator on. At a fast idle it was putting out about 14.6 to 14.7. This is a a reduction of 0.2 to 0.3 volts. Once I kicked it down off of the fast idle it was down to 14.3 to 14.4.

This leads me to believe that I have an over achiever for an alternator. It's going to ride in the trunk as a spare and will be serviced after Carlisle.

Check the field wiring on that alt. Run w the one now installed, for sure. Good to see you won't cause your battery to blow through the hood. :D
 

Gerald Morris

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Just curious, what BRAND of alternator is the "over-achiever?" Could this one possibly have a heavy current stator? Lower impedance would draw more current, resulting in the stronger field which would produce higher voltages. Was it rebuilt by somebody special?
 
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