64 Val alt swap questions

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Slim Flipmin

Slim Flipmin

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So i got a new alternator for my car and have a couple questions. The new one says its externally regulated. I thought they were internally reg. Aso my plug size is different.......everything else seems pretty much the same. Any suggestions on swapping the plug, or shiyld i get a different one. Thanks in advance! !
 
Without photos (or a link to what you bought) we have no idea at all what you are referring to.
 
Here are a couple pics. This is the alternator I pulled out of the car. Stud on the left and the terminal at the 6 o'clock position are my connections.
 

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OK so you put a later squareback on your car. Are you staying with the original 64 style regulator? (69 and earlier)

You are on the right track, as the "squareback" is a better design and will give you better low RPM output. If you keep the "old style" regulator wiring, you want to buy a modern "name brand" replacement, if you do not now have a replacement that is electronic guts instead of the original mechanical. Easy way to tell is look at the bottom of the regulator. Two large resistors means old mechanical. "Nothing much" under there means electronic.

In that case you need to take a meter and make CERTAIN that neither of the two field connections is grounded. If not, pick one and make a ground jumper for it, and hook your original green regulator wire to the remaining one

If you want to use the newer 70/ later regulator, hook it all up as the diagram. You will have to add one more wire, and obtain a connector pigtail for the newer regulator

Your original: ...........You can hook the new one up as original by grounding one field

pic1.gif


Converting to the newer regulator: You add one more wire from the second field connection up to the IGN wire of the regulator

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Came from here:

http://www.mymopar.com/index.php?pid=78
 
Here is the new alt. in the car. I figured it's the same connections but the terminal blade is a different width . The little green ground you can almost see in the bottom of pic......unconnected. Can anyone confirm?
 

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Doesn't matter which field is which, since both are isolated from the case, and doesn't matter which way the field current flows. For other readers with a pre-1971 (or so) original alternator, it does matter since one field is grounded to the case, but they also have only one field terminal so nothing to mix up.

First I have seen of wide-blade terminals. Might have started in 1980's vehicles, since they used the square-back alternator perhaps into the 1990's. You could swap in an earlier brush set (ebay). I would just remove those brushes and file down the width. You could also make a short adapter jumper, or there may be 1-piece adapters in the bubble packs at auto parts. For the jumper to ground, I would just change the mating connector, since that part isn't original to your car anyway.
 
Slim Flipmin said:
Ok, cool. If i run it the original way does it matter which field terminal i ground onto?
Click to expand...


CHECK THAT neither is GROUNDED. This is VERY important. If the one there is too wide, just use the other, but CHECK with your meter.
 
If you got a squareback, why not just run an electronic voltage regulator? Its a good upgrade. Easy cheesy upgrade, just 1 extra wire and a splice. The dual field electronic regulates the ground connection so its VERY important to make sure neither spade is grounded or the alternator will go full tilt charge on you.
 
Ok. So I called it a ground and it is actually the Field wire that runs back to the regulator. I ordered a new regulator and removed the old one. So, if I upgrade the setup will I run another wire from the other "field" terminal to the "ignition" terminal on the regulator? Thanks for all your input!

Here is the pic of my old reg. Is the OE or not?
 

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Yes, that's the old "mechanical." So far as I know all replacements are actually electronic. I'm not sure there's a real advantage, either way, to a replacement for that, or convert to the new style.

Couple of things

Make CERTAIN the regulator is GROUNDED and make certain you don't have a voltage drop problem to the new one. You can easily check that after you get things installed and working.

With the engine running and warm (regulators are temp compensated) and with the battery "normalized" that is run enough to be fully charged, make these tests:

GROUND

For the ground test, make this first with all accessories off, and the engine running at a fast idle to simulate "low speed cruise."

Then make the same test again, with lights, heater, etc powered on

Set your meter for low DC volts. Stab one probe right into the top of the NEG battery post. Stab the other into the regulator mounting flange. Be sure to penetrate rust, chrome, paint. You are hoping for a very low reading, zero is perfect. More than .2V ---2/10 of one volt--- you have a grounding problem

POSITIVE

To check the positive side of things, start as above with engine running to simulate low cruise speed. Measure the battery voltage accurately and post it. You are looking for not less than 13.5, not more than 14.8 or so, and "optimum" is 13.8--14.2

If the voltage is higher, you need to check for harness voltage drop.

To do that access the "key" ignition run coming out of the bulkhead to the ballast resistor. The VR "IGN" terminal is the same point.

Hook one lead of your meter there, and the other stab into the top of the battery POS post. Once again, you are hoping for a very low reading. More than .3V means you have a drop problem somewhere in the harness---that is the circuit path from the battery to the VR
 
To help others, did you run a 2nd field wire to use the later Vreg (~1971+, triangular connector)?

As mentioned, you could have used your original wiring. I bought an electronic Vreg for my 1964 & 65 cars on rockauto (~$11). Same connectors, same 1-wire to alternator (other field terminal still grounded). It was much smaller and chrome.
 
I have a question for you. Was this a new or rebuilt alt ? Also do you know what AMPs the old one was and the new one is... I ask this because mopar wiring back in the day was great when it was new, but with age it gets dangerous as I'm sure all that own these cars can tell you.. I read all the things to do to help reduce the risk of fire. I did all of them and one day I had smoke rolling out from under the dash and hood... If your new alt is a higher out put than your original(which was probably a 30amp w/o ac) you really need to upgrade your harness... I ended up building a new harness for my car and up grading to bigger primary wiring.. I would tell anyone that keeps the amp meter to do this before the smoke shows up.. These old early A's didn't have a bunch of extras so the wiring is simple to pull.. Takes a couple of hrs to pull harness. You can get all the correct terminals on line.. Like I said I only replaced the primary wiring and some of the secondary from the fire... Do Not crimp, but solder and seal with heat shrink sleeves. I choose not to break the wire from the alt that goes to the amp meter and back out... This was one of the trouble areas with the old wiring. This also makes it easier to clean the bulkhead connection. I hope this info helps someone out there.. I was lucky when mine burned, it was in the garage so just burnt wiring... Anyone have any questions on this just ask.. Just one more thing, if you build a new harness you won't be able to find the correct color coded wire.. so make notes on what you did different from factory so the next owner knows what wires are running...
 
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