External voltage regulator for engine swap

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Kaelinator

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Hi y'all,

I've been swapping a 5.7L hemi engine into my 1995 YJ. I got this alternator from a junkyard 2007 Ram 1500. I had it tested at O'Reilly's and it passed all the tests.

I'm using a Holley Terminator X Max, so I can't control it using the stock ECU.

So I've been trying to wire this thing so that it gives me the voltage I need. I've purchased a voltage regulator only for it to charge at 17.5V. That's my issue. I have
pin one connected to the middle pole of the regulator as well as my ignition, as stated in the diagram of the voltage regulator. I have the second pin wired to the other pole on the voltage regulator, again, as stated in the diagram.

I've placed an order for an adjustable voltage regulator but it won't be in for a week or so. In the meantime, does anyone have any ideas? I'm out at this point.

Thank you in advance.
-Kael

1664582692321.png1664582789894.png
 
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Kaelinator

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According to this source, I can control the alternator by grounding the field circuit. I tried it and it doesn't seem to care much if I ground a pin while the other is on +12V.

I have hardly any information about these alternators and I'd like to know more. Any resources are appreciated.
 
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Kaelinator

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The yellow one came with the voltage regulator, white one is just more clear. I've also confirmed that I have good ground.

1664588057345.png1664588122522.png
 
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Kaelinator

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Do you have a ballast resistor?
I'm unsure. That should sit between my ignition (like they keyed +12V) and my ignition coil? I'm using coil on plug, not a distributor. I tried putting a 194 bulb in series between keyed +12V and the middle pole of the voltage regulator, but then I get no charge.
 

Oliver Closehauf

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Can you show a picture of the regulator where the plug plus in and a shot of the actual plug?
 
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Kaelinator

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So have you done this test?

View attachment 503308
Okay I've tried this. Very odd behavior. With the voltage regulator unplugged, the following happened:

Started engine by jumping it
Removed ground jumper cable from jeep so that it's no longer getting power from donor car
Voltage kicks up to 17V

I then turned it off. I didn't get the chance to ground that wire that I had jumped from the connector. This is the exact same behavior as if I didn't wire the voltage regulatorup in the first place.
 
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Kaelinator

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Can you show a picture of the regulator where the plug plus in and a shot of the actual plug?
2022-09-3022.22.402946964107205297995.jpg2022-09-3022.23.287108136992227000264.jpg2022-09-3022.24.08536284302749211112.jpg
Just took these. Green wire from connector is only connected to pin 2 on the alternator connector. Blue wire is connected to pin 1 on alternator connector and to keyed +12V. Continuity has been checked. I'll gladly take more photos. Thank you so much for your help. 2022-09-3022.27.49174647471751106382.jpg
 

pacofortacos

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Do you get no charge if the plug is off of the alternator?
Also check both pins on the alternator and see if one of them gives continuity between the pin and ground (alternator case).

"Started engine by jumping it
Removed ground jumper cable from jeep so that it's no longer getting power from donor car
Voltage kicks up to 17V
I then turned it off. I didn't get the chance to ground that wire that I had jumped from the connector. This is the exact same behavior as if I didn't wire the voltage regulatorup in the first place."

So if I am following correctly, you have + voltage going to one pin 1. Pin 2 is to the voltage regulator only. AND with the plug plugged onto the alternator but unplugged from the voltage regulator - you get 17 V. Correct??

That regulator controls the ground side of the field.
 
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Kaelinator

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Do you get no charge if the plug is off of the alternator?
Also check both pins on the alternator and see if one of them gives continuity between the pin and ground (alternator case).
Correct, no charge. And you're right. Pin 1 is grounded to the case, but pin 2 isn't. Pin 1 is the one that is hooked up to my ignition!! Ahh I'll try flipping the two and seeing if that works.

I've seen no documentation saying that the pins matter as to which is wired where, in fact they've all said the opposite. We'll see if this is the issue.
 

Oliver Closehauf

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With the field plug un plugged you should not be getting any voltage (just battery voltage). Possibly a blown diode in the alternator allowing your full battery voltage to back feed and provide max field voltage? Wild guess. Late for me. I'll check in in the morning.
 

pacofortacos

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If pin 1 is grounded to the case, your setup won't work ( I don't think). The 2 wire system usually uses 1 wire for + and 1 wire for - and then regulates usually the ground side but it can work by regulating either side.
.
I wonder if something happened to the alternator of if it is supposed to be grounded and the pin is some sort of feedback.

One pin could be a reference wire for the PCM, and in that case the field is control by the + voltage to the field - since the ground side is already grounded internally.

Or something is wrong with the alternator and that pin 1 shouldn't be grounded to the case. I can't find anything that indicates that it has an internal ground.
 

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    95 charging system.jpg
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Kaelinator

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With the field plug un plugged you should not be getting any voltage (just battery voltage). Possibly a blown diode in the alternator allowing your full battery voltage to back feed and provide max field voltage? Wild guess. Late for me. I'll check in in the morning.
Maybe? Would this not've shown up on the test it did at O'Reilly? 2022-09-3023.32.538210079008545957959.jpg
 
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Kaelinator

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If pin 1 is grounded to the case, your setup won't work ( I don't think). The 2 wire system usually uses 1 wire for + and 1 wire for - and then regulates usually the ground side but it can work by regulating either side.
.
I wonder if something happened to the alternator of if it is supposed to be grounded and the other pin is some sort of feedback.

One pin could be a reference wire for the PCM, and in that case the field is control by the + voltage to the field - since the ground side is already grounded internally.

Or something is wrong with the alternator and that pin 1 shouldn't be grounded to the case. I can't find anything that indicates that it has an internal ground.
Do you know of any documentation that says pin 1 shouldn't be grounded? I'm unsure if this means I need to completely rethink my strategy for controlling this alternator or if I should get a new one. I'll be up bright and early at O'Reilly tomorrow if it's just blown.
 

pacofortacos

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my 2001 dakota manual shows it as ungrounded also. Same as the diagram I attached.

Here is a 2006 Ram charging diagram.
It also shows it as ungrounded except by the wiring from the PCM.
 

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