Dash volt gauge

[AJ71DUSTER]

Does the Dash volt gauge control the charging system? on 71 duster, sometimes I get a charge sometimes the gauge just sets in the middle and does no move Not even a flicker even when you turn everything on I mean everything
issue's
1 when charging no issue gauge will flicker between middle of gauge to 40+ side
2 when stuck in middle of gauge with nothing on but car running pull pos side off battery car will run.
3 all the same as above in 2 turn lights on car pull pos side off battery car dies ..
Use a jumper wire on Voltage Reg still does not show charge on Volt gauge
New Alt
New Volt Reg
Drove car this morning to work charged all the way . out of work started car up volt gauge stuck in middle got home battery dead, jump to start,

This issue's is not all the time

 

[72bluNblu]

It's not a volt gauge, unless you changed it. It's an alternator gauge, and it measures AMPS not volts. And yes, all of the cars alternator output runs through that gauge. I'll let 67Dart273 handle the rest of it. Del?

 

[AJ71DUSTER]

It's not a volt gauge, unless you changed it. It's an alternator gauge, and it measures AMPS not volts. And yes, all of the cars alternator output runs through that gauge. I'll let 67Dart273 handle the rest of it. Del?

Thanks for the reply, I hope Del is not tired of explaining again,,lol

 

[AJ71DUSTER]

Thanks for the reply, I hope Del is not tired of explaining again,,lol

Ok I have seen another post on here referring to Madelectrical.com that was posted by Del I was hoping that this info will work for me , in the other post they were referring to a dodge truck the system looked the same just would like to confirm that I could it on my 71 duster,

 

[67Dart273]

The actual name of the "gauge" is "ammeter." But I would not "blame" it per se. There are several things could be wrong, including stuck/ gummed up/ worn down brushes, loose belt, and so on.

So start with the belt. Inspect the belt and pulleys for glazing, wear, damage, and check belt tension. It should be very difficult to turn the fan blade (if not a clutch) by hand.

Next, you need to try and get the thing to "quit working" and GINGERLY check a few things while it is not working. I say "gingerly" because if it's a loose connection, you could unknowingly wiggle it and remake the poor connection

"If" you can get it to act up, make a few voltage checks. Keep the engine running fast idle, and learn how to "hand kick" the fast idle / choke "up" so you can leave it hands free.

With the system "broke" confirm by watching the ammeter, turn on the lights. Should show discharge if the trouble is present

Next measure voltage at the alternator output stud, and right at the battery. "No charge" the system should be below 13V or less, same at the alternator stud. If the alternator stud is "way high" 15--16V or higher but the battery is below 13, then you have a loose / bad connection in the main charge lead. Bad bulkhead connection, ammeter, etc

Next, measure voltage at the alternator BLUE field connection. Do this without disconnecting anything. It should be very close to "same as battery."

Now, measure GREEN field lead. It should be quite low, that is, the regulator is "controlling the ground" at that point.

If this gets you nowwhere, dismount the VR, scrape around the mountings and re-mount the VR using star washers The VR MUST be grounded.

Next inspect the VR connector. use a light, look for corrosion and looseness, and work the connector in/ out several times.

+++++++++++++++++++++++++++++++++

If the above does not lead to a fix, try bypassing the VR and checking the brushes / field for current draw. You have to be careful here, because some multimeters don't have a current scale large enough, and you can damage some meters. Fluke meters, EG, have fairly expensive fuses in the ammeter circuit of the meter.

Set your meter up for the largest current scale, IE 10A and disconnect the green field wire. Connect the meter from the alternator terminal which you just now disconnected, NOT the green wire, and the other probe to ground. With the key in "run" and the belt loose, turn the pulle slowly by hand. Measure the field draw. You are looking for somewhere in the 3--5A range

I would also remove the brushes and inspect them for wear and gum/ grease / oil etc

 

[AJ71DUSTER]

The actual name of the "gauge" is "ammeter." But I would not "blame" it per se. There are several things could be wrong, including stuck/ gummed up/ worn down brushes, loose belt, and so on.

So start with the belt. Inspect the belt and pulleys for glazing, wear, damage, and check belt tension. It should be very difficult to turn the fan blade (if not a clutch) by hand.

Next, you need to try and get the thing to "quit working" and GINGERLY check a few things while it is not working. I say "gingerly" because if it's a loose connection, you could unknowingly wiggle it and remake the poor connection

"If" you can get it to act up, make a few voltage checks. Keep the engine running fast idle, and learn how to "hand kick" the fast idle / choke "up" so you can leave it hands free.

With the system "broke" confirm by watching the ammeter, turn on the lights. Should show discharge if the trouble is present

Next measure voltage at the alternator output stud, and right at the battery. "No charge" the system should be below 13V or less, same at the alternator stud. If the alternator stud is "way high" 15--16V or higher but the battery is below 13, then you have a loose / bad connection in the main charge lead. Bad bulkhead connection, ammeter, etc

Next, measure voltage at the alternator BLUE field connection. Do this without disconnecting anything. It should be very close to "same as battery."

Now, measure GREEN field lead. It should be quite low, that is, the regulator is "controlling the ground" at that point.

If this gets you nowwhere, dismount the VR, scrape around the mountings and re-mount the VR using star washers The VR MUST be grounded.

Next inspect the VR connector. use a light, look for corrosion and looseness, and work the connector in/ out several times.

+++++++++++++++++++++++++++++++++

If the above does not lead to a fix, try bypassing the VR and checking the brushes / field for current draw. You have to be careful here, because some multimeters don't have a current scale large enough, and you can damage some meters. Fluke meters, EG, have fairly expensive fuses in the ammeter circuit of the meter.

Set your meter up for the largest current scale, IE 10A and disconnect the green field wire. Connect the meter from the alternator terminal which you just now disconnected, NOT the green wire, and the other probe to ground. With the key in "run" and the belt loose, turn the pulle slowly by hand. Measure the field draw. You are looking for somewhere in the 3--5A range

I would also remove the brushes and inspect them for wear and gum/ grease / oil etc

thanks for all the great Info looks like I have some checking to do Thanks again

 

[AJ71DUSTER]

thanks for all the great Info looks like I have some checking to do Thanks again

update
main battery stud on alt 15v
blue wire on alt with key on not running 10.4
Green wire at alt .8 not running
Battery 12.0
Main black wire going in bulk head on firewall 15v
If this is the correct way to test , please advise me if not I will start over,,,then it seems to be that I have got a bad socket or wire under the dash /bulkhead?
With the alt at 15v and new would not think it is bad ?
I put a jumper wire across the VR terminals and seen no improvement on my amp gauge,I have done that before to help trouble shoot VR, all the time I was testing car was in (broke mode) never got it to charge at all
what is hard to understand car will run with amp gauge in middle all day long with battery unhooked, but when lights turned on it dies. thanks

 

[mguner]

Headlights draw a lot more AMPS than the ignition and it is quite possible you have voltage drop through the bulkhead connectors amplifying the typical low output of Mopar alternators at idle......

 

[AJ71DUSTER]

Headlights draw a lot more AMPS than the ignition and it is quite possible you have voltage drop through the bulkhead connectors amplifying the typical low output of Mopar alternators at idle......

agreed it's just been a goose chase with all of the possibilities, for sure it has not been a quick fix...
looking for validation on the above test before I move on I feel that I have reduce some of the variables before I pull the drivers seat and start under dash fun LOL

 

[67Dart273]

update
main battery stud on alt 15v
blue wire on alt with key on not running 10.4
Green wire at alt .8 not running
Battery 12.0
Main black wire going in bulk head on firewall 15v
If this is the correct way to test , please advise me if not I will start over,,,then it seems to be that I have got a bad socket or wire under the dash /bulkhead?
With the alt at 15v and new would not think it is bad ?
I put a jumper wire across the VR terminals and seen no improvement on my amp gauge,I have done that before to help trouble shoot VR, all the time I was testing car was in (broke mode) never got it to charge at all
what is hard to understand car will run with amp gauge in middle all day long with battery unhooked, but when lights turned on it dies. thanks

It's very important to read these exactly as I detailed, and detail the conditions as such. You say "battery 12V" Is this running, not running, at low speed idle, higher "cruise" RPM, and are accessories like headlights on or off?

The 15V at alternator stud shows it is trying to charge, you need to find out why that is not reaching the battery.

At the moment, your no1, 2, and 3 suspects are the black and the red large wires going into / out of the bulkhead, and the ammeter and it's wire terminals.

If you have not done so, read the Mad article, that diagram is a very good overview

Catalog

 

[AJ71DUSTER]

It's very important to read these exactly as I detailed, and detail the conditions as such. You say "battery 12V" Is this running, not running, at low speed idle, higher "cruise" RPM, and are accessories like headlights on or off?

The 15V at alternator stud shows it is trying to charge, you need to find out why that is not reaching the battery.

At the moment, your no1, 2, and 3 suspects are the black and the red large wires going into / out of the bulkhead, and the ammeter and it's wire terminals.

If you have not done so, read the Mad article, that diagram is a very good overview

Catalog

Alt stud was 15v running ay about 1300 rpm
the battery, blue wire and green were not running with key on,, I was afraid to touch my meter to the blue and green on the alt when is was running. would I put red on wire then touch black to ground and the same with green , just afraid of a shorting out my system
I did trace black wire from Alt stud to firewall when running found out that I had 15v going into firewall also found fuseable link thats connected to red wire going to battery no volts there so I do believe that my problem is somewhere under the dash . I do want thank you for to replies , I did see the mad article that you had posted on another post have it and printed it let me know what you think THANKS AGAIN

 

[67Dart273]

OK with the engine running at 1300, confirm the alt is 15v, then also immediately measure the battery posts. It SHOULD be same voltage. If it is turn on some loads, heater, lights, etc, and see if it holds same.

 

[AJ71DUSTER]

OK with the engine running at 1300, confirm the alt is 15v, then also immediately measure the battery posts. It SHOULD be same voltage. If it is turn on some loads, heater, lights, etc, and see if it holds same.

Ok sure will , thanks again