Alternator Pains

[Henry T]

Seems like my alt voltage is high.I'm reading between 14.3 to 14.5 volts and if I stand on the gas as high as 15.I did some checking and tried another regulator and no help looks like a voltage drop to the regulator.So thinking of going with a one wire alternator or conversion kit but noticed the setpoint of those are as high as 14.8 volts is it just me or doesn't that seem a little on the high side?And if I drive with the headlights on it usually stays at 14 volts.Any imput would be greatly appreciated Thanks

 

[Dana67Dart]

14.3-14.5 is not high if the battery is recharging.

15 is a bit high.

What year is the car?
What has been modified to the electrical system?

 

[Henry T]

The car is a 73 swinger hasn't been much change in the wiring I cleaned up a few not so great looking things and ran a new wire from the alt straight to the guage and then to the relay on the fender getting it away from the fire wall connector.That was a few years ago.

 

[George Jets]

Did you replace the original voltage regulator?

All aftermarket voltage regulators are made in China, some fail right out of the box, some just don't work right if they work at all.

I went with an Alternator conversion setup with a add on one wire voltage regulator that fastens to the back of the alternator. It is adjustable output too. Mine was set fine at 14.3 output... happy with that.

'89 D100 had onboard computer controlled voltage regulator that failed. Ditched that and went with the 1 wire setup.


☆☆☆☆☆

 

[RustyRatRod]

So you're just arbitrarily going with a one wire alternator with no diagnosis? Who's to say you won't still have the same problem if you don't find out what it is NOW? I'm not understanding everyone's fascination with just throwing parts at something. Yall all must have more money than me.

 

[Dana67Dart]

The car is a 73 swinger hasn't been much change in the wiring I cleaned up a few not so great looking things and ran a new wire from the alt straight to the guage and then to the relay on the fender getting it away from the fire wall connector.That was a few years ago

So all was working correctly then something happened?

The way your alt works is...

There is a switched battery voltage feed that comes from the ignition switch.

That goes to one of the field terminals on the alternator. (Blue wire)

The green wire that goes from the other field terminals to the voltage regulator provides a variable ground via the voltage regulator.

The other wire that goes to the voltage regulator provides a voltage signal to the regulator to tell the regulator to increase or decrease the charging voltage.

If that wire has lower than battery voltage that will induce an over voltage charging situation.


With the car running, you need to check voltage from battery negative to voltage regulator positive input and the switched field terminal voltage.

Both should be very close to battery voltage.

 

[Wayne Rider]

Dana67Dart I am not real smart and I have a 75 Dart Sport that isn't charging . I have power on blue wire to alternator 12 volts and ground on green wire . I had a spare voltage regulator and tried it , same thing, not charging . I know with todays questionable new parts it is possible but is it possible both voltage regulators are bad or am I not understanding correctly ? Any help is greatly appreciated

 

[RustyRatRod]

Dana67Dart I am not real smart and I have a 75 Dart Sport that isn't charging . I have power on blue wire to alternator 12 volts and ground on green wire . I had a spare voltage regulator and tried it , same thing, not charging . I know with todays questionable new parts it is possible but is it possible both voltage regulators are bad or am I not understanding correctly ? Any help is greatly appreciated

This is @Henry T's thread. You'll get more and better results if you start one for you. Not to mention you won't be highjacking Henry's thread by posting your own. Since it's likely the two of you have different causes, this will only serve to convolute his thread.

 

[Henry T]

I have a voltage drop at the regulator of about .7 of a volt and from the reading i've been doing i think would make the alt increase the voltage roughly that amount.I'm not the person to throw parts at something i actually did a bit of testing.I traced the voltage drop to the inside plug on the fire wall that kind of leads me to believe it may be some resistance in the ignition switch.I also checked the wiring around the choke as its the same cir that goes to the alt and regulator. The choke has a heater witch may cause a voltage drop.By removing the choke wire with car running and engine cold watching a meter the voltage would change but only .1 So with the possibility of the ignition switch being the problem i thought a 1 wire alt might be solution to eliminate some of the 50 year old wiring and also solve the problem.It seems to have happened over time i have a volt gauge in the car and confirmed correct with my meter.It kind of puzzels me that I get 15 volts at high rpm wouldn't the regulator hold the voltage at a certain amount no matter how high the rpm.Thanks for the help and i didn't buy that one wire alt yet lol i'm open to any suggestions.

 

[Dana67Dart]

kind of puzzels me that I get 15 volts at high rpm wouldn't the regulator hold the voltage at a certain amount no matter how high the rpm.Thanks for the help and i didn't buy that one wire alt yet lol i'm open to any suggestions

How old is your battery?

Have you tried using a known good battery in place of your current.