Alternator Crashed

[3rdmdqm]

I'm pretty sure the alternator on my deuce crashed. I noticed the volt guage reading at the yellow/green line, then when starting the truck the guage went all the way left. Now its in the yellow. Put a meter on the batteries, they are 24 volt. When turn the power to the guages on, voltage dropped to 23.8 while running. So we put the meter on the alternator itself. Get 24 volts when not running and 24 volts running, so I know it is getting power from battery. Then when running and turn on power to guages and/or lights, voltage drops to 23.8 again at alternator. Shouldn't alternator be cranking out about 27 volts at least? Revving engine does nothing to output. Also, tried turning the hex adjustment screw for the alternator, nothing, no change. Am I missing something here or is my alternator dead? Should I try getting original alternator rebuilt? Its on a 1984 White LDT engine, but deuce itself is a 68. Avengeusa looks like he has a nice replacement alternator for a reasonable price, probably cheaper than trying to rebuild mine. Suggestions?

 

[Westech]

no its dead, but first check all the wires and make sure there good.

 

[jfnemt1ff1]

I'm pretty sure the alternator on my deuce crashed. I noticed the volt guage reading at the yellow/green line, then when starting the truck the guage went all the way left. Now its in the yellow. Put a meter on the batteries, they are 24 volt. When turn the power to the guages on, voltage dropped to 23.8 while running. So we put the meter on the alternator itself. Get 24 volts when not running and 24 volts running, so I know it is getting power from battery. Then when running and turn on power to guages and/or lights, voltage drops to 23.8 again at alternator. Shouldn't alternator be cranking out about 27 volts at least? Revving engine does nothing to output. Also, tried turning the hex adjustment screw for the alternator, nothing, no change. Am I missing something here or is my alternator dead? Should I try getting original alternator rebuilt? Its on a 1984 White LDT engine, but deuce itself is a 68. Avengeusa looks like he has a nice replacement alternator for a reasonable price, probably cheaper than trying to rebuild mine. Suggestions?

He does have a good product, I have one on one of my trucks works great. And a nice guy to deal with.
John

 

[3rdmdqm]

I checked them. We pulled the cover off the alternator where the leads connect and put a meter on it right there. It wasn't showing anything, just 23.8 volts with the power lever to the guages on. I'm guessing if it were working, it would have to be reading higher than that.

 

[3rdmdqm]

Thanks John, I apprciate the feedback on that. I think I'm leaning in that direction.
Dan

 

[ctmustang]

Did you mean you tried turning the hex adjuster. That's not the adjuster but the cover. At least the ones I've seen is a philips head adjuster. Take out the hex and insert philips screwdriver. I set mine at 27.5 volts and been working great eversince.
C.T.

 

[3rdmdqm]

Oops, yes that's what I meant. So I guess the only way to be absolutely sure is to take the positve terminal off the batter while its running and see if the alternator is putting out anything at all correct? And is it possible that a bad ground would cause the alternator to not put out any voltage at all? Or would putting the meter on the alternator terminals tell right away if the alternator was bad?

 

[ctmustang]

you definately don't want to ever pull a battery cable off of anything with the engine running as this will cause a spike and usually end in catostrophic failure of the alternator. Yes check voltage at the alt. with engine running. And yes clean ground at alt. and frame. If nothing then probably time for a new alt.
C.T.

 

[tedstrucks]

I sell used, good (tested) take-offs for $100. email or call me for info

 

[agood1]

I went the used route when mine died, it lasted 2 days and died also. So I found a local guy to rebuild my original one. $125 and it is now a one wire alternator. No longer need the exciter wire.

 

[tedstrucks]

It's rare to find someone that will even work on the military alternators, let alone do it at such a reasonable price.

 

[agood1]

Yeah, this old guy has been in the business for many years. He knew exactly what it was when I dropped it off. Took him about a week. I have not installed it yet...but it should work fine as he tested it before I got it back.
The cool thing is I don't need the exciter wire any longer, so if the batteries are dead, the alternator will still recharge them without needing voltage to kick off the alternator.

 

[stumps]

Yeah, this old guy has been in the business for many years. He knew exactly what it was when I dropped it off. Took him about a week. I have not installed it yet...but it should work fine as he tested it before I got it back.
The cool thing is I don't need the exciter wire any longer, so if the batteries are really dead, the alternator will still recharge them without needing voltage to kick off the alternator.

The alternator needs field current to generate power. No field, no power. The one wire alternator setups get the field current from the battery they are charging. If the battery is stone dead, the alternator will not put out any voltage.

-Chuck

 

[agood1]

Agreed, but it takes less voltage than the two wire exciter to start the field.

 

[stumps]

Agreed, but it takes less voltage than the two wire exciter to start the field.

Why do you think this?

All I have seen done in other 1 lead alternators is they put the regulator inside of the alternator, and hooked up the voltage sense lead to the battery terminal of the alternator.

-Chuck

 

[agood1]

Because the guy that built it....told me so. He has been in business for over 30 years.

 

[stumps]

Because the guy that built it....told me so. He has been in business for over 30 years.

Thank you.

-Chuck

 

[ctmustang]

 

[agood1]

I got my rebuilt alternator installed tonight...when I tried to start the truck, the batteries were dead. So I jumped it and got it started. The gauge showed it was charging as soon as it started. My other one would take a couple seconds.

 

[stumps]

My one wire 60A alternator starts to charge instantly too.... but then, so do all the other alternators in my "stable".

Glad to hear you are back in business.

-Chuck