good day juts wondering i have an issue with charging on my 340 duster altenator and VR both test fine when i jumper the VR plug it charges but wont charge when pluged in to VR i have checked plug and conection is fine i have power at blue wire on plug when key is on seems it would point to VR but i have tested it and it works i also have tried several others and its still wont charge
charging issue
- Thread starter seitz
- Start date
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What car?
What year?
What electrical modifications?
What was done to the car right before the issue started?
What year?
What electrical modifications?
What was done to the car right before the issue started?
WATCH THEM BOTH!!!!
69 down
70 up
69 down
70 up
1970 duster 340 all origanal electronic ing car is a full resto never had it running so it’s an orig harness for the electronic ing
Mattax
Just the facts, ma'am
That car came with points ignition so its not original harness or ignition.
It did come with transistorized voltage regulator and isolated field alternator.
Mattax
Just the facts, ma'am
If you jumper the VR plug on an isolated field circuit, nothing should be completing the circuit.
So my guess is that its wired wrong.
Post photos of your alternator from the rear.
post photos of your voltage regulator
post photos of your voltage regulator
Mattax
Just the facts, ma'am
This sticky explains the parts and how they work.
www.forabodiesonly.com
Identifying Chrysler Alternators (1960-1976)
Roundback and Squareback refer to the style of housing. Roundback through model year 1969. Roundback for model years 1970-71 usually has a slightly different rear housing Squareback Revised Squareback Is most easily differentiated by the thin middle between the housings. Overall these...
www.forabodiesonly.com
as mattax pointed out if you have electronic ignition and your wiring is OEM and set up for that it must be a later year harness OR it has been hacked.
How did you test these?
How did you do this
The voltage regulator is providing a variable ground on the green (IIRC) wire to one of the alternator field terminals
The other wire in the VR connector provides switched 12V power to run the VR.
IF you put 12V to the Green (IIRC) wire from the VR to the Alternator and the alternator and wiring is correct the alternator field would have 12V on both ends and no field magnetism would be created and no charging would happen.
IS THE VR GROUNDED?
How did you check this
That is normal
How have you tested the VR?
if you substituted other VRs and still no charge then that would point to the wiring as you stated that when you " jumped" the connector it charged.
I suspect I know the issue but need to see the back of the alternator photos before I move on
Mattax
Just the facts, ma'am
Your telling us that
The field circuit is completed through ground.
So, a more complete illustration of the current flow through the rotor is
You removed the plug and jumpered the terminals and found the alternator powered up.
Lets put a jumper in the illustration.
That's not possible if wired correctly.
How do the electrons get back to the power source?
If it was miswired so the other brush grounds, then it could work like this.
Reasons include wrong alternator (grounded brush) as just discussed in Uncle Punchy's thread, or a wiring fault.
This is how field current is supposted to flow through the rotor when voltage is lower than the set point.
The field circuit is completed through ground.
So, a more complete illustration of the current flow through the rotor is
You removed the plug and jumpered the terminals and found the alternator powered up.
Lets put a jumper in the illustration.
That's not possible if wired correctly.
How do the electrons get back to the power source?
If it was miswired so the other brush grounds, then it could work like this.
Reasons include wrong alternator (grounded brush) as just discussed in Uncle Punchy's thread, or a wiring fault.
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Yes I know I converted to electronic so later year harness and dizzy it’s a valiant duster harness
What Mattox is saying is correct. If you jumper the two VR wires together, and everything else is correctly wired and connected, IT SHOULD NOT CHARGE as you will have 12V on both sides of the rotor
The alternator field blue is switched 12V right from the key
If you jumper the VR blue to green you have just done the same thing---provide the very same source to the remaining brush.
The / a CORRECT ways to test an otherwise properly wired 70/ later system is to
1...Remove the green from the alternator and ground that alternator field terminal. See if it charges. This checks the blue field wire/ wiring, the alternator, and the output charge path
2....Reconnect the green field wire, and disconnect the blue field wire and ground that alternator terminal. Jumper across the VR connector. See if it charges. This checks the VR wiring from the key to the alternator, and again, the alternator and the output charge path wiring.
The alternator field blue is switched 12V right from the key
If you jumper the VR blue to green you have just done the same thing---provide the very same source to the remaining brush.
The / a CORRECT ways to test an otherwise properly wired 70/ later system is to
1...Remove the green from the alternator and ground that alternator field terminal. See if it charges. This checks the blue field wire/ wiring, the alternator, and the output charge path
2....Reconnect the green field wire, and disconnect the blue field wire and ground that alternator terminal. Jumper across the VR connector. See if it charges. This checks the VR wiring from the key to the alternator, and again, the alternator and the output charge path wiring.
Mattax
Just the facts, ma'am
That's a great, straight forward explanation of how to test.
Would you post photos of the back of your alternator.
just reading these post now my alt iam using is a single field my harness only has the green wire and the black Bat wire. I will try a 2 field alt today and see if that is the issue i will ground the seciond field wire on the 2 field alt. VR is grounded and i teseted it with a multi meter plus i tried several Vrs and all had same result
Is this a foreign built car AKA Mexico or Europe? Does it have the factory harness as far as you know? All 70 and later cars SHOULD have had the flat electronic regulator, and isolated field alternator.
If you are sure about this, you can convert to a 2 wire field setup by adding one wire. You need to branch in and connect to the "run" wire from the key, which feeds the ballast, and connect that to the second field, then add the flat 70/ later VR and a connector pigtail. It will connec to the present wires on your 69/ earlier VR, green to field terminal and blue to IGN terminal. VR MUST be grounded.
So far as testing, since you seem to have a grounded field, all you need do is two things:
1...Jumper 12V to the alternator field terminal and run and see if it charges
2...If not put a voltmeter on the output stud and make sure voltage reading. Low voltage, when jumpered and running, below 13V means not charging. VERY high voltage say, 16 and higher, but with 13 or below at battery, means the output circuit is open.
ok guys thanks you for all the input ended up the incorrect alt and a bad wire its up and charging now i just have to get my ralley dash gauges working i have installed new sending units but cant seem to get any of them working. its very tight to get at under the dash i have very slight power coming from the wires to each sender seems very dull and flashes slightly. i beleive i shoudl have 5 volts at these wires which i do 5 plus minus i have good grounds at block and dash and column
The thing to do is not worry about the voltage because there is no set value that you can test for. Either take a spare fuel sender and set it for the test resistances, or drum up some resistors. There are three values for the three gauges, oil, fuel, and temp, all same values, for empty, 1/2 scale, and full scale.
so i got the gauges to move but now the go to far right. i have 11 volts at the secondary terminal at each gauge but it flashes so this i assume is what the VR does so the voltage fluctuates down to 5 volts. this also tells me VR is working i actually install an external VR and it does the same as the one in the fuel gauge. question now is why do my gauges go all the way to the left when key is turned on
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