No charge

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Penstarpurist

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Okay, I'm needing some advice. 1966 valiant /6 nephews car. Was having a charging and starting problem. Starting problem solved with a new ignition tumbler. Charging system still an elusive mystery. Had alternator tested, it was a newer unit anyway but it tested good. Replaced resistor, solenoid,regulator, battery (was bad), cables, connectors to alternator, still wont charge the battery. When we bypass everything and jump from alternator to battery it charges. Loom is old, but no obvious suspect wires. Did replace one that looked iffy. I know I'm overlooking the obvious im sure. Weather is getting cold and rain in the forecast so gotta get the nephew back on the road as he is walking to work right now.
 
Still won't charge on the gauge or confirmed with a VOM?
And you have tried full-fielding it right; and then it works.
If that is correct then you have exactly three options;
1) a faulty regulator ground, or
2) wrong voltage into the regulator, or
3) bad regulator

The most common problem is #1; the regulator must be connected to the battery negative terminal. Follow the ground path and clean all connections.
After that, check the voltage going into the regulator and compare it to the battery voltage; it should be within .5 volt. If it isn't, then you gotta go hunting for the why.
If that is also ok, then, I'm assuming your '66 still has the mechanical VR. Sometimes the points stick, and sometimes I have had success with tapping the metal case, and sometimes it just keeps on doing it again. It's been decades and decades since I worked on one of those so I can't tell you how to fix that.
 
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AJ is correct

What do you mean "bypass everything?" Just exactly what are you bypassing?

START by going to MyMopar and downloading the closest thing to the correct service manual and wiring diagram on that site

If you are jumpering to the field (push on/ flag terminal) on the alternator, you have bypassed the voltage regulator. To check the wiring in that circuit, disconnect the VR and jumper those two wires together, and see if it again charges. If so MAKE CERTAIN the VR is actually grounded, and if so, and it still does not charge, replace the VR

The dark blue wire going to the IGN terminal on the VR should have "same as battery" with key in the "run" position

You made any wiring changes lately?
 
The factory gauge shows neutral. As in no charge or discharge. Then when we go from flag on alternator to battery the gauge shows charging. We also tested the output at the battery as 12.8 and diminishes more when the headlights are put on, or a blinker. The charge falls away and headlights dim. We have replaced the voltage regulator as well. No new changes to the wiring. He's been driving the car for several months and it just began running down on charge, then developed the ignition starting issue on top of it.
 
Oh. Also have the fsm in the car. Thick book, covers everything in '66. I told the nephew he needed to have one of those before he even drove the car. He actually bought one right away for it. So I've got the complete wiring diagram for it.
 
So you have replaced the VR? Only two more things I can think of. Either the green wire goes from VR F terminal to the alternator Field is open/ shorted or the thing is not getting battery voltage from the ignition switch

Unhook both ends of the green, at the VR and the alternator F terminal. Should show zero ohms from one end to other, and infinity (open) to ground.

Double check that with everything hooked up "normal" you are getting 12V at VR IGN terminal, and "some" voltage at the green F terminal at the alternator. Again, this is with all wiring connected

"New" does not mean "good." (functional.) You might have a bad VR, or something unforseen----careless short, etc, may have destroyed the new one.

You might want to do an alternator field current test. Look in your service manual, the section on charging system in chapter 8 Should draw somewhere between 4--6A just off the top my head
 
I replaced the green wire as it had open breaks. I'll double check my work again. I was thinking about a faulty out of the box Vr. Its been known to happen. Initially when we tested the output with the wires out, it showed continuity. When we hooked it back up and tested it, we got 12.5 volts. I'll do a field current test next.
 
Aw Hell,
I thought "No Charge' ment he was giving something away LOL. Seriously though, if you have voltage at the regulator field connection with key on and engine running check the field connection at the alternator. If there is voltage at the regulator and not at the alternator then you have bad wire. If you have voltage at the ignition terminal of the regulator and none at the regulator field connection you either have a bad regulator or a bad ground.
 
Then when we go from flag on alternator to battery the gauge shows charging.
So if I understand what was done correctly, full fielding at idle speed produces a enough power to recharge the battery. yes?
(The flag terminal feeds the field.)

We also tested the output at the battery as 12.8 and diminishes more when the headlights are put on, or a blinker. The charge falls away and headlights dim.
Try this above idle speed - say 1250 rpm. Also checking voltage at the regulator in (blue) and the alternator output (stud) will also narrow down the problem. It should be the same at all three locations.
 
Okay I will test a few more areas like you described and make sure all grounds are cleaned and tight. I will get back at it tomorrow when it gets warmed up a bit outside. I may order another Vr for it to have that as a last resort.
 
Grounds are not the issue, at least "not yet." Grounds can cause poor starting (cranking), stuff not to work well (dim lights etc), and erratic or over-voltage charging. But they won't cause NO charging. If the grounding was that bad the car would not crank nor run at all.
 
AJ is correct
The dark blue wire going to the IGN terminal on the VR should have "same as battery" with key in the "run" position
If you don't have very close to same as battery voltage at the blue wire with ignition switch on and or engine running, Just to know whats not the problem... You should have a connector at fusible link. Check all those connections to be clean and tight. You have to get 12 volts in and out. A weak connection can signal the starter relay, etc... yet all circuits suffer low voltage.
 
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