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Pulling my hair out charging issue!!! Please help!!

flamesoldier

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I need major help, I have a 1974 Plymouth Roadrunner P Code 400 big block, i have a brand new 100amp tuffstuff replacement alternator, new deka battery, new voltage regulator, all brand new fuses, new ignition coil, i tested the back of alternator car not on it is receiving 12v. I turn car and run it and the car starts draining down the battery from 12v all the way down to 11.5 and further if i let it. The only thing i did was remove the blue tachometer from back of tachometer because the needle was bouncing like crazy. The field wire is blue I noticed do i have to plug that back in to complete a circuit or do i have another issue? Someone please help. I believe my field wires are in correct spots as well

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Take the two small wires off the alternator. Then.
1-Verify there is battery voltage at the big battery feed wire at the stud. If you do next step.
2-Verify you have keyed battery voltage at the blue wire. If so then plug it on the field spade. Next step.
3-With the car running jump the other field spade to a ground. It should full field and be charging hard. If not its the alternator.
Reason I unhook the wires when testing is to eliminate feed back through the alternator.
 
Take the two small wires off the alternator. Then.
1-Verify there is battery voltage at the big battery feed wire at the stud. If you do next step.
2-Verify you have keyed battery voltage at the blue wire. If so then plug it on the field spade. Next step.
3-With the car running jump the other field spade to a ground. It should full field and be charging hard. If not its the alternator.
Reason I unhook the wires when testing is to eliminate feed back through the alternator.

I just did part one and two and they passed. i also have the factory style voltage regulator instructions for new alternator say use tuff stuff regulator 7545 you think because i have a factory specific regulator that could be the issue

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I just did part one and two and they passed. i also have the factory style voltage regulator instructions for new alternator say use tuff stuff regulator 7545 you think because i have a factory specific regulator that could be the issue

View attachment 1402052
Did you do step 3 as I illustrated?
 
I had problems with '72 Satellite, since getting it running the headlights would alternate between dim then brighten up, tried replacing regulator problem still occurred. (Also bypassed ammeter to remove another known failure point.) Lived with it for awhile then alternator died, replaced it and it worked for a month then battery was dead again, alternator checked good, tried another new regulator, still no charge.

What I found was the wires were corroding internally, insulator looked good but copper was dark with a bit of green here and there. Replaced wires and connectors and got new pigtail for regulator. Works good now with headlights a constant brightness, plugged original regulator I thought was bad back in and it works fine with new wiring.

Also using relay for battery power as I had voltage drop from bad wires and old connections. Relay also feeds ignition coil as that also had low voltage, symptom was would start and rev OK but would backfire when under load. Car had sat a few years outside without hood and fender that might have helped wiring fail. Factory also might have got some bad wire back in the day.
 
I just did the most it shows is 11.81 v still not performing i have used 2 brand new alternators with same result and they test at autozone fine
 
I just did the most it shows is 11.81 v still not performing i have used 2 brand new alternators with same result and they test at autozone fine
When you checked for battery voltage at the stud were the two small wires unplugged from the alternator?
 
Yes the 2 small wires were off, i did more testing, i read in the key on position the blue field wire should match battery, my battery states 12.00 and the blue wire either side bith read the same 9.63 v now what
 
Yes the 2 small wires were off, i did more testing, i read in the key on position the blue field wire should match battery, my battery states 12.00 and the blue wire either side bith read the same 9.63 v now what
Run a hd jumper from the alternator stud direct to the battery. Hook up the blue wire, run and ground the alternator field male spade brush terminal and then see what it does.
 
I figured out the issue the previous moron owner switched #22 brown and #23 blue wires in bulk head
 
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