Not Charging, pulling my hair out.

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74Dusted

74Dusted

Stock Piler of 340's
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My '84 D50 won't charge (70's Dodge Wiring & Charging System)

I have Battery voltage (12.9 volts) to the Voltage Regulator and at the Stud on the back of the alternator. Checked the wiring to/from the alternator & regulator for resistance, none worth mentioning (0.00 - 0.01)

Had a Square Back Alternator on the truck, replaced it with a spare. No difference.

Replaced the regulator, still not charging

Slapped on a Nippondenso 90 Amp Alternator (Tested at Autozone, Good. Even though it was pulled from a vehicle that charged fine) Still not charging

Swapped parts from my '73 Duster onto the truck (Regulator, Alternator), still not charging. Even though the parts on the Duster charged just fine 2 minutes before that.

Ran new wires to and from the Voltage Regulator and Alternator. I even replaced the Pigtail/Plug/Connector at the Voltage Regulator. Still not charging. WTF?!!!!

I've replaced every thing on the truck related to the charging system (And I do mean everything) and it's still not charging. Voltmeter in the truck is showing 12.x volts and slowly decreases as the engine runs (obviously). Multimeter at various points under the hood (alternator stud, battery, starter relay, etc) shows the exact same thing. Turning on anything (lights/radio/wipers/brake lights/etc) immediately causes the Voltmeter and Multimeter to plummet into the 11.x voltage range, showing that the truck isn't producing even the slightest hope of charging.

So far there's no money spent, since I always keep brand new spare parts around for my dodges, but this is royally irritating me.
 
With the reg unpluged you should have battery voltage at the blue wire at the alt end and the reg end, with the key on. The reg case has to be grounded to the body AND the engine has to be grounded to the body.
 
69MOPE said:
With the reg unpluged you should have battery voltage at the blue wire at the alt end and the reg end, with the key on. The reg case has to be grounded to the body AND the engine has to be grounded to the body.
Click to expand...

I do (even though my blue wire is actually a Green Wire).

Regulator has a dedicated Ground Wire running directly to the battery (as do the lights on the truck, and the aftermarket ignition, and the wiper motor, etc)

I have a 0 Gauge Ground Cable connecting the Battery to the Engine & Battery to Frame. and 2 Gauge cables connecting Engine to Body and Body to Battery. Most of the wiring is extremely overkill on this truck.
 
74Dusted said:
I do (even though my blue wire is actually a Green Wire). Regulator has a dedicated Ground Wire running directly to the battery (as do the lights on the truck, and the aftermarket ignition, and the wiper motor, etc) I have a 0 Gauge Ground Cable connecting the Battery to the Engine & Battery to Frame. and 2 Gauge cables connecting Engine to Body and Body to Battery. Most of the wiring is extremely overkill on this truck.
Click to expand...

Check that again, green is field and blue is hot!
 
69MOPE said:
Check that again, green is field and blue is hot!
Click to expand...

I can, there's no blue wire on this truck though (never was). The Ignition & Charging wiring came from a 1976 Dodge Truck, they didn't use the (later style/traditional) Blue/Green color scheme. It's actually Green/Red. Hmm. I just checked it.

I've got 12.9 volts (Battery voltage) to both the Green and the Red with the Key on. Both at the regulator and at the alternator. Which makes sense, since they complete a circuit and the regulator supplies a pulsed ground to regulate voltage.

The only modification I made to that wiring (other than a Ballast Resistor Delete to run an Accel 300+ Ignition System) was to run the Alternator Charge Wire direct to the Battery instead of through the Bulkhead (Since I have a Voltmeter).

I even removed/bypassed the Fusible Link on the Charge Wire, to see if it might have burnt out.
 
Did you swap batteries also? May have some shorted or sulfated cells that freak over anything other than surface charge....
 
OK, a primer. I assume you are using a 70 / later Mopar regulator. Here is a simplified diagram

HOW THIS WORKS. Wire from IGNITION 1 is switched "ignition run" what Ma calls IGN1. This is hot in run. It feeds 12V to the VR IGN terminal, and 12V to one field terminal

The "F" (field) OEM green, is a "controlled ground" by the regulator. To put simply, the VR controls field current by controlling the ground on this field terminal. More field current, more alternator output. More shaft speed, more output

The VR MUST be grounded. MUST

Dual_Field_Alternator_Wiring.jpg
HOW TO BYPASS the regulator:

There are a few pitfalls here.

You may have a break in your charging line, you may have problems with the alternator, and you may have troubles in the field circuit

To boil them all down, do this: REMOVE both field wires.

Take a pair of clip leads and ground either one of the fields. Clip the other one to a battery source DO NOT clip it to the output stud

Start and run, (good fast idle) see if battery voltage increases, and if not....... Measure running voltage at a good fast idle at the alternator stud

"Same as battery" IE 11.xx --12.6 means it's not charging, you hooked it up wrong, or the alternator is bad

"Anything" 13 and higher up to say, 15 means it's charging. So far so good

"Very high" IE above 15 volts means you have a break in the charging line
 
If the above test shows an increase in voltage at the battery, that is "shows charging" Move on

Now, hook up the switched ignition wire to either field. Key on........engine off.... Set your multimeter for high DC current. Hook it between the remaining field and ground. You should read 2-3 or more amps draw

If you have no multimeter, again with key "in run" use a clip lead in reduced light, and ground the remaining field. You should see a small spark.

Clip the lead to ground, start and run the engine, fast idle, and watch battery voltage

If you see an increase, so far so good.

=========================================================

Next, remove the VR connector and devise a way to jumper the two terminals togehter at the connector. Machine screws work.

Hook the "would be green" from the VR to the alternator to one field. Clip the other field to ground

Repeat, run engine see if it charges

If so, the field wiring is all good, and the alternator is working

=========================================================

The VR ABSOLUTELY must be grounded MUST. Clean it, mount tight, use star locks. "Jack" the connector in/ out several times to feel for tightness and scrub the terminals. Inspect them visually for corrosion.

Hook all up normally and test. If no charge, replace the VR
 
I'll do some more testing/work when it stops raining. Currently pouring outside and I don't feel like messing with electricity when I'm soaking wet. :D
 
Is the voltage regulator grounded good? I know it needs to be on the a bodies not sure about the trucks
 
Yeah, the regulator is grounded (has a ground wire from the case, direct to the battery).

I'm just gonna limp it over to my shop in the morning. I pulled the Marine Grade 65N Series (850/1000CA) Battery out of the compartment under the bed (was/is my dedicated Winch battery) and installed it in place of the Primary Battery to run the truck.

One nice thing about that monster Marine Battery, it doesn't matter if it's charging or not, it'll power something for a long time (have used it to drive vehicles that didn't charge, in the past)

If I get it over to the shop, I can do a lot more than I can with a few hand tools, a multimeter and swearing. :D
 
Fixed.

I pulled my hair out for a long time.

Get this, my new Nippondenso 90amp had broken brushes, snapped off halfway. I'm thinking it might have taken a hard hit/fall at some point.

The alternator off my Duster, I turned it over to check a few things and the Bridge/Diodes fell out in chunks. I grabbed a used Square Back Mopar alternator (that needed brushes) off the shelf, slapped some used brushes in it, truck charges again.
 
Great!! Thanks for the update. Makes some of us feel like some of this is actually worthwhile.

"It's blue"
 
67Dart273 said:
Great!! Thanks for the update. Makes some of us feel like some of this is actually worthwhile.

"It's blue"
Click to expand...

I'm sorry it took so long for the update, just fixed the truck a few minutes ago. A lot of family problems (separate problems with separate family members), stress, a lot of banging my head against the wall, 3 hours of sleep a day and running at the absolute ragged limit
 
Good work. I have had "all of above" in various Mopar cars.

My 69 Dart wouldn't charge even after a new alternator. I connected a jumper cable from the new alternator's case to BATT- and the ammeter then showed "C". It was a bad electrical connection between the case and block (aluminum is tricky).

My 82 Aries, w/ square-back alternator (same as later Darts) would burn up the 3 floating diodes every year like clockwork (even in winter). I became proficient at splitting it open underneath the AC compressor (since a pain to remove that) and replacing just the diodes. By cutting cooling slots in the diodes, I got them to last >2 years. I attributed it to the transverse engine layout not giving enough air flow thru the alternator.
 
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