2 wires for alternator but three connectors, which two?

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Jayman62

Jayman62

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I have a 1966 Dart with a 225 slant six, the car did not have an alternator when I got the car so I bought one from NAPA. There are two wires near the alternator area. One is a round hole post connector, the other is a spade connector.

The alternator has three connections, 1 is a post connector and there are two spade connectors. The post is obvious but I'm not sure which spaded connector to use. The one not connected appears to be marked FLD. My battery does not appear to be charging, but headlights, wipers, turns signals all work fine. The dash ammeter gauge will move when the lights, wipers and signals go on.

The question now is am I missing a wire for the alternator, did I choose the wrong spade connector, or do I have the wrong alternator? Maybe it's connected properly and I have another issue.

Thank you

Jay

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Do you have the original style ('69 and older) regulator? If so, hook the green wire to the field terminal(either one will work) and ground the unused terminal to the case. Or you can run a wire from the unused terminal back to the blue wire on the voltage regulator. If you have the '70 and newer voltage regulator then you will need to run a wire from the 2nd terminal on the alternator back to the blue wire of the regulator regardless. Or simply locate an alternator that has just one field terminal on it like this one on RockAuto: More Information for ACDELCO 3342086

'69 and older looks like this.
Standard Motor Products VR101 Standard Motor Voltage Regulators | Summit Racing

'70 and newer looks like this:
Mopar Performance P4529794 Mopar Performance Voltage Regulators | Summit Racing
 
Jayman62 said:
I have a 1966 Dart with a 225 slant six, ]
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What you have there is a 70/ later alternator. That uses a different VR BUT YOU can easily use it on your older vehicle.

FIRST MAKE CERTAIN that the two field (spade) connectors are OPEN to GROUND. This is because many rebuilds come IN correctly assembled, or with insulators left out of the field/ brush assemblies

If the field is open (infinity) to ground, simply pick either and wire it to ground. Connect a short jumper wire with a female spade to a ground screw. ALTERNATIVELY remove the insulator and replace it with a washer. Some work well that way and others are more difficult. In any case ground one field, then connect it as you would have your old one.
 
67Dart273 said:
What you have there is a 70/ later alternator. That uses a different VR BUT YOU can easily use it on your older vehicle.

FIRST MAKE CERTAIN that the two field (spade) connectors are OPEN to GROUND. This is because many rebuilds come IN correctly assembled, or with insulators left out of the field/ brush assemblies

If the field is open (infinity) to ground, simply pick either and wire it to ground. Connect a short jumper wire with a female spade to a ground screw. ALTERNATIVELY remove the insulator and replace it with a washer. Some work well that way and others are more difficult. In any case ground one field, then connect it as you would have your old one.
Click to expand...

67Dart273 sir, for Jayman's reference...By "old one" is it safe to say you are referring to a '69 and older, single field terminal style alternator? He did say his car did not come with an alternator when he got it so he has nothing to reference here.
 
Thanks guys, I would assume I have the same VR that came with the car (or one similar if it had been replaced by a previous owner) NOTE I just checked and the VR is older style.

67Dart when you say open to ground, do I check resistance from the terminal to a ground point and look for 0's on the meter? Sorry, for my lack of understanding with the terminology.

So if I'm reading correctly just ground one of the spade connectors and all should be good?
 
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Zeros on a multimeter indicate a short. You are looking for open to ground as 67Dart273 stated. With one test lead on the alternator terminal and the other on the casing it should read infinite, not zero. Ground one terminal of the alternator you have pictured and then yes, you should be all set. I personally would prefer the green wire connected to the the terminal marked "FLD" instead of the unmarked one. Looks more intentional:). And be sure that VR is for your era. Unmistakable to distinguish the two.
 
PlymCrazy said:
67Dart273 sir, for Jayman's reference...By "old one" is it safe to say you are referring to a '69 and older, single field terminal style alternator? He did say his car did not come with an alternator when he got it so he has nothing to reference here.
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That's correct PlymCrazy I have no old alternator to reference.
PlymCrazy said:
Zeros on a multimeter indicate a short. You are looking for open to ground as 67Dart273 stated. With one test lead on the alternator terminal and the other on the casing it should read infinite, not zero. Ground one terminal of the alternator you have pictured and then yes, you should be all set. I personally would prefer the green wire connected to the the terminal marked "FLD" instead of the unmarked one. Looks more intentional:). And be sure that VR is for your era. Unmistakable to distinguish the two.
Click to expand...

I definitely have the older style VR, thanks for the clarification on the meter setup. Do I do this test with the car running or ignition on? Really appreciate all the help!
 
Engine off. This test can be done with the alternator in or out of the vehicle. To eliminate any confusion disconnect any wires going from the car to the alternator while you have the meter hooked up.
 
Jayman62 said:
The alternator has three connections, 1 is a post connector and there are two spade connectors. The post is obvious but I'm not sure which spaded connector to use. The one not connected appears to be marked FLD
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Assuming you ordered an alternator for your correct year... AND assuming the rebuilder did the job correctly. The "FLD" terminal visable in your first photo is grounded internally to the case of the alternator. The terminal is clipped off so you can not attach anything to it.

The dk. green wire from your voltage regulator should hook to the other "FLD" terminal on the alternator, it will have an intact terminal.

This is assuming you are using a 69 and older voltage regulator. Looks like a black block with 1 screw on terminal and one press on terminal

If you are not charging then either...

  1. The new alternator is defective
  2. The wiring from the voltage regulator to the alternator is open or shorted
  3. The voltage regulator is bad
  4. The voltage regulator is not grounded
  5. The 12v feed to the voltage regulator is not feeding 12v

Good info:

Identifying Chrysler Alternators (1960-1976)

69 and earlier



70 and later
 
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doug 371 said:
wrong alternator...your original would have had only 1 spade connection
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That's correct BUT... the rebuilders are in short supply of the "round back" single field wire alternators so they convert the "square back" 2 field wire (isolated field) alternators to work in place of the 1 field wire alternatirs
 
Jayman62 said:
Thanks guys, I would assume I have the same VR that came with the car (or one similar if it had been replaced by a previous owner) NOTE I just checked and the VR is older style.

67Dart when you say open to ground, do I check resistance from the terminal to a ground point and look for 0's on the meter? Sorry, for my lack of understanding with the terminology.

So if I'm reading correctly just ground one of the spade connectors and all should be good?
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Yes, and as someone said, very low or zero is a short. No idea what your meter uses for an "open" or "infinity" indicator, but just turn it on set for some resistance scale, and with the leads unconnected to anything, see what it "says." That will be "open." From field to field should be quite low, just a couple or a few ohms. Either field to ground should be open/ infinity
 
Also, "if you ever want to" you could convert to the 70/ later VR which is much more available and a better design. Just get a pigtail connector for one at NAPA. Ground the VR, hook the blue wire to the old "key switched" blue wire off your old VR, hook the green to the green wire on the connector. Add one more wire from the "key" side of the ballast resistor down to the second field terminal and you are done. One more wire is what this amounts to
 
Dana67Dart said:
That's correct BUT... the rebuilders are in short supply of the "round back" single field wire alternators so they convert the "square back" 2 field wire (isolated field) alternators to work in place of the 1 field wire alternatirs
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That's a shame. I had a whole bunch of good used early alternators a while back and couldn't find a rebuilder that was willing to buy them for any price. They ended up going over the scales.....
 
cudamark said:
. They ended up going over the scales
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That's the shame part.

I had a couple round backs that that happened to too.

That was before I found out about the core shortage. Now I have 5 to 7 lost count core alternators.
 
Jayman62 said:
I have a 1966 Dart with a 225 slant six, the car did not have an alternator when I got the car so I bought one from NAPA. There are two wires near the alternator area. One is a round hole post connector, the other is a spade connector.

The alternator has three connections, 1 is a post connector and there are two spade connectors. The post is obvious but I'm not sure which spaded connector to use. The one not connected appears to be marked FLD. My battery does not appear to be charging, but headlights, wipers, turns signals all work fine. The dash ammeter gauge will move when the lights, wipers and signals go on.

The question now is am I missing a wire for the alternator, did I choose the wrong spade connector, or do I have the wrong alternator? Maybe it's connected properly and I have another issue.

Thank you

Jay

View attachment 1715974833

View attachment 1715974834
Click to expand...
Just put my old alternator off and back on today my spade connector is on FLD and no blade at GND
Jayman62 said:
I have a 1966 Dart with a 225 slant six, the car did not have an alternator when I got the car so I bought one from NAPA. There are two wires near the alternator area. One is a round hole post connector, the other is a spade connector.

The alternator has three connections, 1 is a post connector and there are two spade connectors. The post is obvious but I'm not sure which spaded connector to use. The one not connected appears to be marked FLD. My battery does not appear to be charging, but headlights, wipers, turns signals all work fine. The dash ammeter gauge will move when the lights, wipers and signals go on.

The question now is am I missing a wire for the alternator, did I choose the wrong spade connector, or do I have the wrong alternator? Maybe it's connected properly and I have another issue.

Thank you

Jay

View attachment 1715974833

View attachment 1715974834
Click to expand...
Move the spade connector to FLD and check all connections
 
mrs49 said:
Just put my old alternator off and back on today my spade connector is on FLD and no blade at GND
Click to expand...
Yes on a 1 field wire alternator


mrs49 said:
Move the spade connector to FLD and check all connections
Click to expand...


If the OP touches the single field wire to this wire he will fry his VR.


Red is CUTOFF terminal DO NOT ATTACH ANY WIRE TO THIS TERMINAL IT IS GROUNDED.

fuchsia arrow points to METAL washer grounding this terminal
.

Screenshot_20220823-155424.png





This is a 2 field wire alt wired as a 2 field wire it says "FLD" in both locations AND neither field terminal is clipped off.
Screenshot_20220823-160106.png




This is a rebuilt 2 field wire alternator, internally wired to be used as a 1 field wire.

Big Blue cir is "FLD"
Red points to trimmed off terminal.
Small blue cir shows where the other "FLD" marking is.

Screenshot_20220823-160536~2.png




This is the 1 field wire alternator, marked "FLD" ( blue) and "GND" (green)
Screenshot_20220823-160027.png
 
Dana67Dart is correct the one Field connector is grounded with metal washer and the connector is cutoff, I couldn't put the connector on that terminal if I wanted to or by mistake.

I finally got around to using my Ohm meter. With battery disconnected both Field contacts read 0 on the meter with one probe on the field terminal and one to the block. If I touch the probes together I get a minimal resistance reading.

So now I'm not sure what's going on, maybe I should just replace the (old style, metal box) voltage regulator? I saw the video posted above but I don't have all that test equipment to test it properly without just part swapping.

Suggestions?
 
At first glance of the photos you first posted I didn't notice that the terminal was clipped. I see that now. You say the battery is disconnected when testing, but are all the wires to the alternator disconnected while testing with the meter also? I would disconnect them to eliminate any confusion.
Next, did you check to see if there was a grounding washer in the usable terminal? If there is one in there, remove it. From what you reported it sounds like that one is grounded as well. And the fellas here say it's not uncommon to get one that has been rebuilt improperly.

So I would:

1) Check your meter in the resistance setting. It should read zero when touching both probes together. If it doesn't, use one that does.
2) Assure all wiring is disconnected to alternator.
3) Test both field terminals to assure that one is open to ground (you will later connect your field wire to this terminal) and the other reads zero (you will not connect to this one. This one should be the clipped terminal). Use the casing of the alternator as your ground, not the block when testing.
4) If the FLD terminal you will be using is grounded, either remove the washer if present or go back and get another alternator as the one you have now may be internally shorted. UNDER NO CIRCUMSTANCES SHOULD YOU CONNECT THE FIELD WIRE TO A TERMINAL THAT IS SHORTED AND RUN THE CAR! This will damage some wiring at the very least!
 
PlymCrazy said:
At first glance of the photos you first posted I didn't notice that the terminal was clipped. I see that now. You say the battery is disconnected when testing, but are all the wires to the alternator disconnected while testing with the meter also? I would disconnect them to eliminate any confusion.
Next, did you check to see if there was a grounding washer in the usable terminal? If there is one in there, remove it. From what you reported it sounds like that one is grounded as well. And the fellas here say it's not uncommon to get one that has been rebuilt improperly.

So I would:

1) Check your meter in the resistance setting. It should read zero when touching both probes together. If it doesn't, use one that does.
2) Assure all wiring is disconnected to alternator.
3) Test both field terminals to assure that one is open to ground (you will later connect your field wire to this terminal) and the other reads zero (you will not connect to this one. This one should be the clipped terminal). Use the casing of the alternator as your ground, not the block when testing.
4) If the FLD terminal you will be using is grounded, either remove the washer if present or go back and get another alternator as the one you have now may be internally shorted. UNDER NO CIRCUMSTANCES SHOULD YOU CONNECT THE FIELD WIRE TO A TERMINAL THAT IS SHORTED AND RUN THE CAR! This will damage some wiring at the very least!
Click to expand...

New probing yields these results, I used case of alternator as ground point

My meter when stationary reads 1, if I touch the probes it initially reads about around 14 then almost immediately goes to 0

1. grounded and clipped connector reads 001 with meter set to 2000k ohms (display acts just like when I touch the probes together)
2. other field connector (the one that is normally connected) does not fluctuate like above, unless I touch the screw head, but on the spade connector it reads nothing.

Jay
 
Jayman62 said:
New probing yields these results, I used case of alternator as ground point

My meter when stationary reads 1, if I touch the probes it initially reads about around 14 then almost immediately goes to 0

1. grounded and clipped connector reads 001 with meter set to 2000k ohms (display acts just like when I touch the probes together)
2. other field connector (the one that is normally connected) does not fluctuate like above, unless I touch the screw head, but on the spade connector it reads nothing.

Jay
Click to expand...

From what you stated it sounds like the alternator is testing good. Any idea why the alternator was missing in the first place?
 
Before you start it for the first time with the new alternator installed, verify the field wire is connected from the alternator to the field side of voltage regulator(VR) and that and that the other connector on the VR is connected to keyed 12V. It has me little worried why the alternator wasn't in there to begin with.
 
PlymCrazy said:
Before you start it for the first time with the new alternator installed, verify the field wire is connected from the alternator to the field side of voltage regulator(VR) and that and that the other connector on the VR is connected to keyed 12V. It has me little worried why the alternator wasn't in there to begin with.
Click to expand...
First off thanks for all your help!

I bought the car from a picker who said it was in a barn, with a bunch of other cars, and had probably been sitting since the mid 80s. Throughout its sitting various pieces went missing. One was the alternator, some brake components, etc. So I had to buy a new (rebuilt) alternator.

I've had the car on the road for about a year but only driving it every so often, and had it on a trickle charger. I have lately been driving it more and noticed that the battery was depleting, the other day it turned over very slowly. I recharged the battery but realized that it probably was not charging. So hence the question about the alternator hookup since I was unfamiliar with the newer style conversion for a two wire car.

I'll check the wiring to the VR.

Jay
 
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