Urgent Help with Charging System

[glitch340]

Okay, I know I've talked about it before, but ith the thread title, it may not have been getting the views I needed to help solve my problems.
When I got the car there was no charging whatsoever. I put a new alternator in and it still wouldn't charge. Next I bought a new voltage regulator. Then I went through and cleaned up all the iring running to the voltage regulator.
Still nothing.
Finally I got it to overcharge when I put one voltage regulator on, so I figured I cured the problem and just needed a new voltage regulator.
Bought another voltage regulator and it's back to not charging at all.
Does anyone have any idea what else could be wrong?
I've even tried bypassing the wiring to the voltage regulator running a wire straight from the battery to the voltage regulator and then from the regulator field terminal to the alternator. For some reason both wires that connect to the alternator will read the same voltage, but when I full field the alternator it will produce current.
I'm at a total loss. Any help is greatly appreciated.

[GoodysGotaCuda]

Make sure the voltage regulator has a good ground and good source voltage with the key on. The voltage regulator varies the ground circuit to the alternator. The alternator receives 12v when the key is on, and the voltage regulator varies its ground based on the voltage reading at the regulator. (low voltage, better ground, more current).

Also, I have gone through MANY issues with 'new parts'. I went through two 'new' alternators and two 'new' voltage regulators before I found ones that worked when I had issues with my charging system. I went back and fourth for a good couple weeks chasing it. I have since went and bought a $15 junkyard 90a denso alternator and the $35 mopar constant voltage regulator and have had zero issues for about three years now.

'new' doesn't mean its good. I especially had issues with low end autozone parts.

[72rtchallenger]

Make sure the voltage regulator has a good ground and good source voltage with the key on. The voltage regulator varies the ground circuit to the alternator. The alternator receives 12v when the key is on, and the voltage regulator varies its ground based on the voltage reading at the regulator. (low voltage, better ground, more current).

Also, I have gone through MANY issues with 'new parts'. I went through two 'new' alternators and two 'new' voltage regulators before I found ones that worked when I had issues with my charging system. I went back and fourth for a good couple weeks chasing it. I have since went and bought a $15 junkyard 90a denso alternator and the $35 mopar constant voltage regulator and have had zero issues for about three years now.

'new' doesn't mean its good. I especially had issues with low end autozone parts.

make sure of the grounding

[glitch340]

checked grounds at the voltage regulator, alternator, battery, everything... I even bypassed the wiring with a jumper from the + battery terminal to the ign terminal on the regulator, and then from the field terminal on the regulator to the field on the alternator. And still when I unplug the field wire from the alternator it doesn't register as a ground. It's reading battery voltage. I still wonder if I got yet another bad regulator, but I'd think a bad regulator would mean it would overcharge like the one I know that's bad... I'd have no problem picking up another regulator, it just sucks that the auto parts stores don't do returns on electrical stuff, plus I've been making extra sure on the regulator ground by sanding the paint off of them, so they definitely wouldn't take them back.

[GoodysGotaCuda]

checked grounds at the voltage regulator, alternator, battery, everything... I even bypassed the wiring with a jumper from the + battery terminal to the ign terminal on the regulator, and then from the field terminal on the regulator to the field on the alternator. And still when I unplug the field wire from the alternator it doesn't register as a ground. It's reading battery voltage. I still wonder if I got yet another bad regulator, but I'd think a bad regulator would mean it would overcharge like the one I know that's bad... I'd have no problem picking up another regulator, it just sucks that the auto parts stores don't do returns on electrical stuff, plus I've been making extra sure on the regulator ground by sanding the paint off of them, so they definitely wouldn't take them back.

How did you 'check' the ground at the regulator?

Both fields on the alternator will read source voltage when there is no ground to complete the circuit and use the power. If you can ground the terminal on the alternator that is supposed to end up at the voltage regulator, you should get 'full' output from the alternator. Be sure not to ground the hot wire coming from the harness. If that gives you full charge, the alternator, the charging wire to the battery, and the power to the alternator has just been checked. You are now looking at a harness problem to the voltage regulator from the alternator, the voltage regulator, or the ground of the voltage regulator.

Same thing with a light bulb. If you have power to a light bulb on one wire, the other/ground wire will have 'power' as well until you ground it and the bulb uses it.

[glitch340]

Using a multimeter there was no resistance from the voltage regulator to the negative battery cable. So I knew it had a good ground. I know that it also has power, I've also unplugged the wire from the alternator and tested it at the terminal with the car running, it reads roughly the same voltage as the battery. When I full field the alternator it goes to full charge.

So the only options are:
1) Alternator - Checks OK - It charges when the field terminal is grounded
2) Wiring from Battery to alternator (ignition) - Checks OK - Same as above and has only .2 ohms resistance, and at most a 2 volt drop
3) Wiring from voltage regulator to alternator - Checks OK - Visual inspection, ~.1 ohms resistance at most, allowed alternator to overcharge with other faulty voltage regulator
4) Grounds (alternator, voltage regulator, etc) - All checked, low resistance, and alternator overcharges with faulty regulator so they must be okay
5) Voltage Regulator - - Not sure how else to check it. But everything else checked out okay, so maybe I should try yet another one

If those are the only things that can affect the charging system, then I guess thats the only option left. Thanks for the help guys!

[GoodysGotaCuda]

Using a multimeter there was no resistance from the voltage regulator to the negative battery cable. So I knew it had a good ground. I know that it also has power, I've also unplugged the wire from the alternator and tested it at the terminal with the car running, it reads roughly the same voltage as the battery. When I full field the alternator it goes to full charge.

So the only options are:
1) Alternator - Checks OK - It charges when the field terminal is grounded
2) Wiring from Battery to alternator (ignition) - Checks OK - Same as above and has only .2 ohms resistance, and at most a 2 volt drop
3) Wiring from voltage regulator to alternator - Checks OK - Visual inspection, ~.1 ohms resistance at most, allowed alternator to overcharge with other faulty voltage regulator
4) Grounds (alternator, voltage regulator, etc) - All checked, low resistance, and alternator overcharges with faulty regulator so they must be okay
5) Voltage Regulator - - Not sure how else to check it. But everything else checked out okay, so maybe I should try yet another one

If those are the only things that can affect the charging system, then I guess thats the only option left. Thanks for the help guys!

I think you should try a different regulator myself. As far as checking the regulator ground with resistance, I'm not too keen on that myself. Resistance is a funny reading and kind of play tricks on you. When checking for loss power a voltage drop test is the best method to use. For something like checking the ground on a module or box, I would prefer to take a jumper wire and physically ground the case to a known good ground and see if your results change. Rather than relying on a resistance check.

Resistance can be shown on a meter by one bitty strand of wire touching. That will give you zero ohms of resistance from one end of a wire to another. However, that will not check it's ability to flow current. That one strand can't handle 10 amps, right? So to check that, you put a load on the circuit and check the voltage drop on it using both leads of the meter, from one end to the other of the wire. Since the wiring can't pass the current, you will likely get a high reading like 10v or something. Meaning from one end to the other, 10v is being lost. Far cry from that 'zero ohms' value.

You mentioned a 2v drop from the battery to alternator power field wire. Was that actually measured at 2v drop? That is HUGE! If that same reading is making it to the regulator, it could be your reason the one regulator was 'overcharging' due to it getting a false (low) voltage reading from faulty wiring/connections.

[glitch340]

You're right about the resistance, if I remember right I also went through and tested voltage drop on all grounds. Before I throw in a new regulator I will pull it off the firewall and test it with a jumper to the - battery cable as an extra check.
As for the 2 volt drop (typo) I meant to say a .2 volt drop. When I started it was around 1.2 volts of drop and I cleaned up several connections, like the bulkhead, the nomex connector to the steering column, etc.

[glitch340]

Well... Haven't been down to the auto parts store yet, but I tested the ground on the voltage regulator and it still hasn't fixed the problem. I completely bypassed all the wiring by wiring the voltage regulator ignition terminal straight to the + battery terminal, the field terminal straight to the alternator field terminal, and the voltage regulator body to the negative battery terminal. I also ran a wire from the positive battery terminal to the other terminal on the alternator. So the entire system was bypassed except for the battery, alternator and voltage regulator. Still no charge. Tried the voltage regulator that overcharges, and it still overcharges. The alternator produces current when I full field it so I think it's working plus had it tested when I bought it because I didn't want to get another bad one off the shelf. The battery has been tested and is good to go. So all signs point to the voltage regulator. I guess I'll have to start buying them in bulk or something...
Are there any brands that are better than others? Maybe buy the mopar reproduction one?
So far I've tried two from CarQuest and One from Napa, the one that was originally on the car had a "Select" sticker on it. Not sure where it was purchased, but I'd assume O'Reilly Auto Parts.

[GoodysGotaCuda]

It took a couple of cheap auto parts store ones to get a good one. i find napa and carquest has some better parts. I currently have the mopar performance voltage regulator in mine, no issues at all.

[glitch340]

Update! Turns out it was the voltage regulator after all!!! 
It just kinda pisses me off that neither CarQuest or Napa carried a WORKING voltage regulator.
It's bull**** really, the companies that make them could test them before they sent them out. Kinda mad I blew $45 on voltage regulators and $55 on an alternator plus a good 20 hours or so of checking wires... Only to finally buy a Mopar Voltage Regulator off of FleaBay that works!!! (I'll probably be buying another as a spare). I was hesitant to buy it at first since it was twice the price of the cheap ones, but well worth the price 

[Chryco Psycho]

 
 At least you got it solved

[brads70]

Update! Turns out it was the voltage regulator after all!!! 
It just kinda pisses me off that neither CarQuest or Napa carried a WORKING voltage regulator.
It's bull**** really, the companies that make them could test them before they sent them out. Kinda mad I blew $45 on voltage regulators and $55 on an alternator plus a good 20 hours or so of checking wires... Only to finally buy a Mopar Voltage Regulator off of FleaBay that works!!! (I'll probably be buying another as a spare). I was hesitant to buy it at first since it was twice the price of the cheap ones, but well worth the price 

Hummmm? I too have overcharging issues, with a new VR? It's a Standard product, economy version, that what they could get quick at my local jobber? Is there a Mopar part # I should look for? I see Mancini has a few different VR? I'll pick one up at Carlile in a couple of weeks if someone knows which one I need? LOL electronics is NOT my strong suit?

[BIGSHCLUNK]

I just went through a regulator prob myself. It was supposed to be "the good one" ...chinese made POS! It will make you nuts for sure. Glad you got it handled! 

[brads70]

I just went through a regulator prob myself. It was supposed to be "the good one" ...chinese made POS! It will make you nuts for sure. Glad you got it handled! 

Got any part # for what you used?  I'm still looking?