Smoked a regulator?

[Voodoo]

I searched through a dozen threads relating to alternator/regulator setups and found a million answers but none of them seemed to be confidently relatable to my situation, so here goes.

1966 Charger, originally a bone stock 383 car, now has 440
ACDelco 3342086 Alternator
SMP VR101 Regulator
All new wiring harnesses front to back from Classic Industries

I was figuring just connect the new regulator to the normal connections in the harness, and boom we are good. At first I did not notice that the alternator has TWO spade connectors (sadly unlabeled) rather than just one. I smoked the regulator after hooking these up and putting the key to ACC to test some other circuits for a minute. I then noticed the two spades on the alternator at that point, so I disconnected both connections to the alternator. I put the key to ACC later on (alt still disconnected) and the regulator smoked again! Struggling to understand how that is possible... Anyone got any insight? I am happy to provide any additional info if I missed anything.

 

[twecomm]

Googling ACDelco 3342086 Alternator, pictures of that model shows a dual pulley and rear photos show 2 spade lugs. One spade looks like it's connected to alternator case and the other looks like it's insulated from the case. You may have had the regulators output connected to the wrong spade lug that might be a ground connection. The insulated lug should be the FLD ( Field) terminal that would connect to regulators FLD terminal. That could explain trashing the regulator. My 66 Charger is all original and has a "signal field" alternator, 1 grove pulley, 2 connections on rear of alternator, a single spade lug for FLD from regulator and a threaded stud for alternator output, which is the heavy wire with ring type terminal lug. The case is ground. If you have an ohm meter, disconnect the alternator and measure resistance (ohms) from each spade to case. The un-insulated spade should show 0 ohms, same as shorting the meters leads together. The other insulated spade should show some amount of resistance. That would be the Field (FLD) terminal.
You mention a new wiring harness, may want to verify that the wire you think connects from alt to regulator is the right one..

 

[Bird 426]

I don't think that you can cross the engine harnesses, the regulator, alternator and even the ballast are different. I don't know what he has.

 

[Voodoo]

Googling ACDelco 3342086 Alternator, pictures of that model shows a dual pulley and rear photos show 2 spade lugs. One spade looks like it's connected to alternator case and the other looks like it's insulated from the case. You may have had the regulators output connected to the wrong spade lug that might be a ground connection. The insulated lug should be the FLD ( Field) terminal that would connect to regulators FLD terminal. That could explain trashing the regulator. My 66 Charger is all original and has a "signal field" alternator, 1 grove pulley, 2 connections on rear of alternator, a single spade lug for FLD from regulator and a threaded stud for alternator output, which is the heavy wire with ring type terminal lug. The case is ground. If you have an ohm meter, disconnect the alternator and measure resistance (ohms) from each spade to case. The un-insulated spade should show 0 ohms, same as shorting the meters leads together. The other insulated spade should show some amount of resistance. That would be the Field (FLD) terminal.
You mention a new wiring harness, may want to verify that the wire you think connects from alt to regulator is the right one..

Thank you for this answer. This gives me something I can check! I do have a replacement regulator on the way. The harness I have has a green wire with a sideways connector designed to attach to the screw thread on the regulator at one end, and a matching green wire with a female spade connector right next to the ring terminal that goes on the alternator. I feel pretty confident is the correct wire, however, your point of it maybe simply being on the wrong terminal, the first time and cooking the regulator might be the simple answer. Once I identify the correct terminal for that green wire to go on, do you happen to know if I am supposed to ground the other wire, or simply leave it disconnected?

 

[Iroc78]

I had a similar issue a few years ago. Smoked several Standard Motor Products 101 regulators (or so I thought) only to discover in the very fine print of the instructions that it is normal for the regulator to smoke during the first so many minutes of operation. I'm not saying this is definitely your problem, but it very well could be. I saw the regulator smoking as soon as I turned the key to the on position and assumed I fried it. Needless to say I now have several new regulators that I previously thought I had ruined, but are still good.

 

[RemCharger]

Thank you for this answer. This gives me something I can check! I do have a replacement regulator on the way. The harness I have has a green wire with a sideways connector designed to attach to the screw thread on the regulator at one end, and a matching green wire with a female spade connector right next to the ring terminal that goes on the alternator. I feel pretty confident is the correct wire, however, your point of it maybe simply being on the wrong terminal, the first time and cooking the regulator might be the simple answer. Once I identify the correct terminal for that green wire to go on, do you happen to know if I am supposed to ground the other wire, or simply leave it disconnected?

You check each one for ohms, and don't connect anything to the grounded one.

 

[twecomm]

Sounds like you have the correct green wire. Not all regulators available are the same.. There are the original mechanical types and the more modern day solid state types. Both can look the same and do the same job, just using different methods. If your alternator is working properly, with car running the voltage at the battery should be MORE than 12.6 VDC. More like 13.5. Also important that regulator case has a good ground connection.

 

[Bird 426]

This is confusing to me, you have an old style points regulater, but your new alternator has two spades on it. Isn't that a square back alternator? Shouldn't you have a round back alternator with one spade? How did you connect both spades to your one spade harness? Don't square back alternators usually have an electronic voltage regulator? If you have a square back on a round back harness, don't they just ground one of the spades?

 

[Voodoo]

I don't think that you can cross the engine harnesses, the regulator, alternator and even the ballast are different. I don't know what he has.

You are correct that the wiring is very distinct within the harness. I referenced my factory service manual when making the connections. The ballast resistor connection that is nearby utilizes different colored wires. The regulator uses a blue and blue with tracer wire for the other side and there is only one connection which that available.

I had a similar issue a few years ago. Smoked several Standard Motor Products 101 regulators (or so I thought) only to discover in the very fine print of the instructions that it is normal for the regulator to smoke during the first so many minutes of operation. I'm not saying this is definitely your problem, but it very well could be. I saw the regulator smoking as soon as I turned the key to the on position and assumed I fried it. Needless to say I now have several new regulators that I previously thought I had ruined, but are still good.

I found this same info in a few places, it really might be just as simple as this! Going to verify a few other things to be safe.

Sounds like you have the correct green wire. Not all regulators available are the same.. There are the original mechanical types and the more modern day solid state types. Both can look the same and do the same job, just using different methods. If your alternator is working properly, with car running the voltage at the battery should be MORE than 12.6 VDC. More like 13.5. Also important that regulator case has a good ground connection.

I verified mine is the mechanical type by opening the case, it all looks good in there.

This is confusing to me, you have an old style points regulater, but your new alternator has two spades on it. Isn't that a square back alternator? Shouldn't you have a round back alternator with one spade? How did you connect both spades to your one spade harness? Don't square back alternators usually have an electronic voltage regulator? If you have a square back on a round back harness, don't they just ground one of the spades?

It is not a square back from what I can tell. Those have a distinct "grid pattern" on the square portion of the alternator. It is a remanufactured round back, but for some reason DOES have two terminals. twecomm gave me a way to test which terminal is the correct one, sounds like as long as I use that one it should function like the old style.

 

[Voodoo]

You check each one for ohms, and don't connect anything to the grounded one.

Just to be sure, when you say the grounded one is it supposed to have a visible ground wire to the case? Or is it internally grounded where I would not see anything distinct, and simply rely on the ohm test? I plan on buttoning this up tonight.

 

[RemCharger]

They sometimes ground them by replacing the insulation washers with steel. No actual wire.

 

[Voodoo]

They sometimes ground them by replacing the insulation washers with steel. No actual wire.

Ok got it, thank you.