How to tell if alt. has internal volt reg?

[Gary Spaid]

OK. I am sure this is obvious to most of you but not to me. My alternator appears to be a 2 wire (has green and blue wire terminals). But I cannot tell if there is an internal voltage regulator. How can I tell without removing it, etc.? TIA.

 

[RemCharger]

Old chrysler alts are external regulator.
Maybe you're thinking of a GM

 

[Gary Spaid]

This alternator was installed in 2002 but I only got the car (67 GTX) a few months ago so I wasn't sure what I had. I don't see a vr in the wiring AND the battery drains off badly. Sounds like I need to get and install a vr. It has the Mopar so I am thinking I should get an electronic vr, right?

 

[Nacho-RT74]

Blue and green wires are to feed the rotor. The regulator is from factory tipically on firewall (A bodies on inner fender thought) getting those same wires.

If double field/wire system, blue is positive from ign switch, green is the return to regulator closing to ground to create the fields. Or what is ALLMOST the same, green is virtually a ground signal being switched on/off accordingly to the regulator sensing.

on single field, where just a green wire reachs the alt field, the closing on/off circuit is a positive signal coming from ign switch but running throught the regulator.

 

[Nacho-RT74]

This alternator was installed in 2002 but I only got the car (67 GTX) a few months ago so I wasn't sure what I had. I don't see a vr in the wiring AND the battery drains off badly. Sounds like I need to get and install a vr. It has the Mopar so I am thinking I should get an electronic vr, right?

Without know how your installation was made, this would be the tipical one being double field.

now, the regulator can be black , blue, chromed… without any kind of label… who knows, but that’s the tipical shape and plug.

 

[RemCharger]

This alternator was installed in 2002 but I only got the car (67 GTX) a few months ago so I wasn't sure what I had. I don't see a vr in the wiring AND the battery drains off badly. Sounds like I need to get and install a vr. It has the Mopar so I am thinking I should get an electronic vr, right?

This whole deal sounds weird- post pics of engine bay

 

[RJRENTON]

This whole deal sounds weird- post pics of engine bay

And a few pix of the back end of the alternator.....from your description your alternator it sounds like it MAY BE a '70-'72 round back alternator or a '72 and later square back design, both were the isolated field design .....a pix would be helpful......
BOB RENTON

 

[dadsbee]

This whole deal sounds weird- post pics of engine bay

Exactly. Easiest forum on the net to post pictures, please do so.

 

[Gary Spaid]

Will post pix in the morning.

 

[Gary Spaid]

OK, here are pics, as best as

I can get without help, of the back of alternator, the ecu, and the firewall where there should be a voltage regulator. I believe it was removed...reason unknown. There is no other box hidden down by the ecu.

 

[Gary Spaid]

Here is a better picture of back of alternator. Based on info I have from po this is a March alternator with internal vr. It has the March serpentine belt setup which is why I think alternator is March also. Where would model number be? So how should it be hooked up?

 

[RJRENTON]

Here is a better picture of back of alternator. Based on info I have from po this is a March alternator with internal vr. It has the March serpentine belt setup which is why I think alternator is March also. Where would model number be? So how should it be hooked up?View attachment 1529720

IMO.....the alternator shown in your pix, is a square back design, an isolated field type. From what I see, the BLACK connection (with the hex nut) appears to be the output. Cannot tell where the BLUE wire originates or where its connected. The GREEN wire comes from one brush connection and goes behind a wire bundle? Wether the alternator has an internal regulator cannot be determined from your pix. Not familiar with the MARCH conversation design...MARCH #590...is it similar to a POWER MASTER.? The March 590 is rated @ 100 amps and has an internal regulator......$400 (Summit price) for a March unit seems high.....but....?
BOB RENTON

 

[Gary Spaid]

It appears upper green wire goes to the ground at the ballast resistor but not connected to the ballast resistor. Not sure about lower green wire or the blue wire. I will check a bit later. Wouldn't the black wire be to the battery? Thanks.

 

[RemCharger]

Yes the large wires on the stud are B+ output wires.

 

[RemCharger]

Speculation: if it's internal regulated..the blue wire supplies voltage to turn on the alt.. the green goes to ground to complete the circuit.
Although I have no experience with one of those.
I would ground the green wire at the alt, if that's the case.

 

[70bigblockdodge]

It's a regular isolated field alternator. The flat pack voltage regulator shown in post#5 is were the blue and green go to on a 70 up system. Previous to that the alternator field was grounded to chassis/engine on one side and regulated with other. The green wire going back to ground at the ballast resistor is okay as long as the blue wire is going to regulator. This is opposite of how it is wired from factory. Green wire regulates and other terminal/blue would just be grounded to alternator case. The 1969 and earlier voltage regulator should be bolted to firewall to the left of the ballast resistor.

 

[70bigblockdodge]

If it is a internal regulated alternator why did they leave the terminals on like that. This is why you don't buy generic GM systems and put them on a Chrysler. Now no one knows wtf you have to do to fix it.
Correction, I know how to fix it, but I don't know the manufacturer or PO mindset to fix a problem that was not there was done.
It looks to me like a isolated field alternator from the outside.
Now you have a drain because the PO hooked it up like a GM alternator and it is draining the battery through the field wiring.
Disconnect the green and blue wires and see if you have very low or no resistance across those terminals.

 

[RJRENTON]

From SUMMIT

March Performance Alternators P590​

Part Number: MCH-P590

• 

$339.99
March Performance Alternators
Alternator, 12 V, 100 amps, Polished, Serpentine Pulley, Internal Regulator, Chrysler, Dodge, Plymouth, Each
See More Specifications
Suggest you call MARCH or Summit for more info.
BOB RENTON

 

[70bigblockdodge]

If that is what he has he should disconnect both blue and green wires, then the drain would most likely go away
Should also bypass the bulkhead connection of the charge wires.
1 the ammeter in our cars is not rated to 100 amps
2 the connectors are a known weak spot on the cars with stock 40/60 amp alternators
3 upgrade the output wire gauge or build a parallel circuit with either a fusable link or fuse/circuit breaker to protect the rest of the car
4 carry a fire extinguisher because the wiring is now suspect to how smart the POs(all of them) are. General assumption from my whole life of unfucking GM wiring experts in Chrysler cars is make sure it is a larger fire extinguisher.

 

[RJRENTON]

If that is what he has he should disconnect both blue and green wires, then the drain would most likely go away
Should also bypass the bulkhead connection of the charge wires.
1 the ammeter in our cars is not rated to 100 amps
2 the connectors are a known weak spot on the cars with stock 40/60 amp alternators
3 upgrade the output wire gauge or build a parallel circuit with either a fusable link or fuse/circuit breaker to protect the rest of the car
4 carry a fire extinguisher because the wiring is now suspect to how smart the POs(all of them) are. General assumption from my whole life of unfucking GM wiring experts in Chrysler cars is make sure it is a larger fire extinguisher.

Your Fourth point is well taken......in general, there are too many self appointed experts, or those that rely on "my buddy's neighbor said" syndrome and blindly proceed with something they don't realize the consequences the could occur......AKA....the Mopar ammeter/bulk head connections......just my opinion of course....
BOB RENTON