Help, Please - Gen III Hemi - Voltage Regulator

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sprinter6591

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I have seen YouTube videos on how to wire a voltage regulator on a Gen III alternator. I am using a Hemi 6 control box and running a carburetor. I do not have a computer on the car. Does anyone have a wiring diagram and voltage regulator suggestions on what you do differently when you do not have a computer? Thanks!
 
Same as any 70 and later VR, here:

pic2.gif


The top wire marked "ignition" goes to 12 v that is hot in run. Make sure you check it against battery voltage that it has no drop. That hooks to either alternator field connection, and to the bottom left VR terminal as shown

the other alternator field terminal goes to the bottom right VR terminal as shown.

Be CERTAIN the VR is grounded and has a good ground path to the battery

s-l300.jpg


The terminal in the middle / left of the two is ignition
The terminal at far right is the alternator field
 
Last edited:
67Dart273 said:
Same as any 70 and later VR, here:

View attachment 1715164333

The top wire marked "ignition" goes to 12 v that is hot in run. Make sure you check it against battery voltage that it has no drop. That hooks to either alternator field connection, and to the bottom left VR terminal as shown

the other alternator field terminal goes to the bottom right VR terminal as shown.

Be CERTAIN the VR is grounded and has a good ground path to the battery

View attachment 1715164335

The terminal in the middle / left of the two is ignition
The terminal at far right is the alternator field
Click to expand...
 
My alternator has the plastic plug in for the wires. There’s no determination as to positive and negative. Does it make a difference which one I connect to? Thanks so much for your help!
 
sprinter6591 said:
My alternator has the plastic plug in for the wires. There’s no determination as to positive and negative. Does it make a difference which one I connect to? Thanks so much for your help!
Click to expand...
Sorry, please ignore the above reply. I misunderstood your message, but after reading it again, I have it figured out. Thanks again for your help!
 
Post back if you have issues. No, the field terminals don't matter which/ what. You're welcome
 
Is the voltage regulator required if you retain the gen3 Hemi alternator, harness, and computer?
 
67Dart273 said:
Same as any 70 and later VR, here:

View attachment 1715164333

The top wire marked "ignition" goes to 12 v that is hot in run. Make sure you check it against battery voltage that it has no drop. That hooks to either alternator field connection, and to the bottom left VR terminal as shown

the other alternator field terminal goes to the bottom right VR terminal as shown.

Be CERTAIN the VR is grounded and has a good ground path to the battery

View attachment 1715164335

The terminal in the middle / left of the two is ignition
The terminal at far right is the alternator field
Click to expand...
Installing a 2018 5.7 Gen III in my 64 Dart GT using Holley Terminator. Also using the 2918 alternator tha5 came with the engine. Wired a 1970 up Voltage regulator per your digram in the post. Started the eng and the alt is putting out 28 volts. Immediately shut it off. Any ideas on what next step should be?
 
DaBee said:
Installing a 2018 5.7 Gen III in my 64 Dart GT using Holley Terminator. Also using the 2918 alternator tha5 came with the engine. Wired a 1970 up Voltage regulator per your digram in the post. Started the eng and the alt is putting out 28 volts. Immediately shut it off. Any ideas on what next step should be?
Click to expand...
Either a fault in the wiring or the regulator. Check the to see if the field wire is shorted to ground in the wiring and make sure the regulator field pin at the connector is not shorted to the housing. More rarely, the 12v input to the regulator could have a voltage drop - but it would have to be seeing around 6 volts for what you described.
 
MadScientistMat said:
Either a fault in the wiring or the regulator. Check the to see if the field wire is shorted to ground in the wiring and make sure the regulator field pin at the connector is not shorted to the housing. More rarely, the 12v input to the regulator could have a voltage drop - but it would have to be seeing around 6 volts for what you described.
Click to expand...
I’ll check the wires and the voltage going to the field in the morning. I don’t think there’s a short as all wires are new. Plus I’ll try a different regulator. The one I used was new but you never know with the Chinese parts we have today
 
I don't know about something as late as '18. Check that it has no internal regulator. The earlier hemis had the same setup as "our old cars" build in 70/ later. That is, the two small nut terminals on the alternator were the field/ brush connections. You wired them just like in 70 and later. check with a meter to be sure that BOTH of the field terminals, when disconnected, are open (infinity) to the case. If that is the case, you should have switched 12V "run" voltage going to one of the two, and the second (OEM green) leading to the regulator. If you disconnect the green with it running, it should stop charging.

MAKE CERTAIN the regulator case is grounded
 
DaBee said:
I’ll check the wires and the voltage going to the field in the morning. I don’t think there’s a short as all wires are new. Plus I’ll try a different regulator. The one I used was new but you never know with the Chinese parts we have today
Click to expand...
If the problem turns out to be the regulator - would you be interested in testing one that isn't made in China? I'm getting another round of beta testing ready.
 
67Dart273 said:
I don't know about something as late as '18. Check that it has no internal regulator. The earlier hemis had the same setup as "our old cars" build in 70/ later. That is, the two small nut terminals on the alternator were the field/ brush connections. You wired them just like in 70 and later. check with a meter to be sure that BOTH of the field terminals, when disconnected, are open (infinity) to the case. If that is the case, you should have switched 12V "run" voltage going to one of the two, and the second (OEM green) leading to the regulator. If you disconnect the green with it running, it should stop charging.

MAKE CERTAIN the regulator case is grounded
Click to expand...
Checked all wires. No shorts. Did find I had the gen exciter wires reversed. Checked the ones on my 2027 Ram. So I reversed the wires to match the Ram. Installed new regulator. Still puts out 18.5 volts. Immediately shut off. I’m at a dead end here. Any other ideas?
 
If you unplug the regulator and start the truck, what voltage do you measure?
 

The newer alternator is not the same. The 03-early 08 will accept the old school wiring/regulator. The new stuff is ALL pcm/ecm controlled.
 
DaBee said:
Okay that explains what is happening. Thanks for the info. Not what I was looking for. But good to know.
Click to expand...
Okay I just googled alt for 2008 Charger and the mounts look the same as the later alts. So it should bolt on. Going to get a 2008 alt tomorrow and give it a try. Thanks for the help. Will let you know how it works.
 
The spacing is also different from the early to Eagle. The pulley will be back a bit. Powermaster makes a one wire Eagle alternator. Expensive.
 
408 swinger said:
The spacing is also different from the early to Eagle. The pulley will be back a bit. Powermaster makes a one wire Eagle alternator. Expensive.
Click to expand...
Found another thread on here that talks about replacing the driver with one that Quick Start Auto Electronics makes. Going to call them tomorrow. If that a viable option, it is the direction I’ll probably go.
 
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