How much voltage?

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Hueyjockey

Hueyjockey

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The VR went out on my '65 Dart GT, 273 2bbl. I decided to upgrade to a 70s VR. After the install and re-wire the alternator is putting out some amps and volts. At 700 rpm volts are 17.4, at 1000rpm volts are 18.5, and at 2000 rpm volts are 19.0 all measured at the battery. I'm thinking these numbers are a bit high. Anyone have any idea if theses are out of acceptable range? My concern is frying the cars's electrical system.
Thnx!
 
Round back Alt?

Why go to that regulator? You could have got a nice solid state unit identical to the original that is plug and play.
 
Even the Mopar blue would have been a good choice. How did you wire it and does have a good chassis ground?

And yes that voltage is to high! The battery will cook.
 
image.jpeg
Wired as per the diagram. And yes, the VR seems to be grounded well.
 
So you ungrounded the second brush on the round back?

Or do you really have a dual field square back?
 
You've misread the recommendations and diagrams; there is no using the '70-up voltage regulator with a '69-down alternator (unless you do some ugly hacks to the grounded brush on the '69-down alternator). You need a '70-up "dual-field" alternator (one with two 1/4" spade field terminals, each attached to a brush that is completely isolated from ground) -- either a '70-'71 roundback or a '72-up squareback.

(If you are determined to keep the alternator you have, then an appropriate regulator, not the '70-up type, is called for. I like the Standard Ignition № VR-128 best.)
 
Not sure.

"Probably" does not not sound firm to me!!!! Concerning the second field!

I have always run the appropriate VR on the the alternator/charging system used! Just my thinking I guess. I do not have items requiring more power than my stock set-up can give me and have always believed the original engineering was adequate based on that.

I know lots of folks have modified and updated and truly believe some of this has sorta got lost in translation and have seen multiple approaches and mixes of it used often with incomplete information! Sometimes seemingly to the point of no approach! I will let some others follow up and watch were it leads you! I always prefer to take the KISS approach, unless I need more than what the factory design gives me.
 
slantsixdan said:
You've misread the recommendations and diagrams; there is no using the '70-up voltage regulator with a '69-down alternator (unless you do some ugly hacks to the grounded brush on the '69-down alternator). You need a '70-up "dual-field" alternator (one with two 1/4" spade field terminals, each attached to a brush that is completely isolated from ground) -- either a '70-'71 roundback or a '72-up squareback.

(If you are determined to keep the alternator you have, then an appropriate regulator, not the '70-up type, is called for. I like the Standard Ignition № VR-128 best.)
Click to expand...

That's the info I was missing. Thanks Slantsixdan
 
Yeah, it's not helpful the outline diagram of the alt doesn't even resemble what you are dealing with as a "tip-off" for the unfamiliar..........................
 
Test w/ a multimeter. With both field terminals disconnected, you should read >1000 ohm to BATT- from both. A 1965 alt should have a single field terminal. The other brush is grounded, which is why it won't work w/ a 1971+ Vreg. Those use "low-side switching" vs "high-side" in your car. I use a later square-back and later Vreg in my 1965 Dart.
 
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