Need help gauge showing discharge....

[williaml]

I have a 65 Dart. When I purchased it most of the lights worked, not all but most. I now have all the lights and such working. My problem is I was checking the ground wire on the alternator alternator brushes fell apart in my hand. I replaced the alternator and everything works but now when I turn on the lights the gauge on the dash shows it is discharging. When I'm driving it never really goes to the charge side of the gauge and whether I rev the engine or not doesn't change the position of the gauge. Not sure if something happened or if all is well. Before changing the alternator it seemed the needle was always charging a little or discharging a little but not like it is doing now.

This board is great and I have received a lot of great help....Thanks for all who answer.

 

[Bulldozer]

I have a 65 Dart. When I purchased it most of the lights worked, not all but most. I now have all the lights and such working. My problem is I was checking the ground wire on the alternator alternator brushes fell apart in my hand. I replaced the alternator and everything works but now when I turn on the lights the gauge on the dash shows it is discharging. When I'm driving it never really goes to the charge side of the gauge and whether I rev the engine or not doesn't change the position of the gauge. Not sure if something happened or if all is well. Before changing the alternator it seemed the needle was always charging a little or discharging a little but not like it is doing now.

This board is great and I have received a lot of great help....Thanks for all who answer.

here you go ,read through this thread http://www.forabodiesonly.com/mopar/showthread.php?t=173673

 

[67Dart273]

I'm assuming you are using the original style 69/ earlier alternator with ONE field terminal, but you may have installed a 70/ later alternator which has TWO field terminals. Eyeball your alternator and see if there is an unused push-on wire connector

Make a quick check. Disconnect the green (push on) field lead and install a clip lead between the output stud of the alternator and the field terminal on the alternator. You should see a small spark in a dark/ shadowed area

Start the engine and slowly bring up the RPM. The ammeter should show a charge. Don't overdo RPM because you have bypassed the regulator

IF this does not happen, your trouble is most likely

You have a late (70/later) alternator and need to GROUND the remaining field terminal

You have a defective replacement alternator

Something else is wrong in the system Post back with results.

The photo below shows an original style "early" (69/ earlier) alternator. The insulated field connector is at the left side of center, the grounded brush is on the bottom. The hole at 12 o'clock is a popular mod "back then" by rebuilders. they used to drill a hole in the case, and install a special insulated brusholder to convert early alternators to the 70/ later style

The photo below shows a later style alternator with TWO insulated field connectors (70/ later) IF you have this situation, all you need to do is run a jumper wire to ground on one terminal, and hook the other up as your old one

This is the "earliest" of the isolated field/ 70 and later designs known as a "roundback"

The alternator below is also a later design with two field terminals, known as a "square back" Same deal, you can ground one field and hook up the other

 

[williaml]

I see another push terminal saying GRD so I should run a wire from that terminal to a ground on the car?

 

[67Dart273]

I believe yes. The ground terminal should be grounded for a 69/ earlier, but this might be one that a rebuilder converted to isolated, or insulated. You can ground it to "anywhere handy," even one of the alternator case screws.

If you have a multimeter/ continuity checker, check across both field terminals. You should show continuity. IF IT has been converted to a 70/ later "isolated field" NEITHER terminal will show continuity to ground.

It would help if you can post a photo. What was the part no. of the one you bought?

 

[cudamark]

I see another push terminal saying GRD so I should run a wire from that terminal to a ground on the car?

That's not usually necessary for most applications as the grounding of the alternator is done through the case. I have seen some rebuilders that add the terminal however. (just to confuse everyone!) The round back cases have GRD cast into them next to a hole where a terminal can be attached but unless the alternator is rubber mounted or isolated in some way, it's not needed. I bet your harness doesn't have a ground wire in it does it?

 

[williaml]

the invoice reflects part #7000
the yellow terminal is the one I tried
as per the tip from the earlier post. It didn't change the needle still indicates discharge.
any help would be appricated.

Thanks

 

[67Dart273]

OK, let's start from scratch. Disconnect the connector at the regulator. Turn the key to "run" engine off

Remove both field leads at the alternator. Use your meter or test light, one of 'em should be hot with key in run.

Put this lead on one of the field terminals.

Use a clip lead and hook the other field terminal to ground. Start the car and see if it charges, easy on the RPM

 

[williaml]

OK, let's start from scratch. Disconnect the connector at the regulator. Turn the key to "run" engine off

Remove both field leads at the alternator. Use your meter or test light, one of 'em should be hot with key in run.

Put this lead on one of the field terminals.

Use a clip lead and hook the other field terminal to ground. Start the car and see if it charges, easy on the RPM

Remove the connector at the voltage regulator on the fire wall? then un-do the leads at the alternator? sworry I'm kind of new at this. The help you have given me to this point i cannot tell you how much I appricate your help.

 

[67Dart273]

What you will be doing is known as "full fielding" the alternator. You need to identify which field wire is switched 12V. That is the only reason for removing the regulator connector -- to remove that wire from the problem.

Then with the key "in run" you should have ONLY ONE of the two field wires with 12V hot.

Hook that field wire back up to the alternator.

Now you should have the second field terminal on the alternator not hooked to anything.

Take a clip lead and ground that terminal.

With the engine running, the alternator should be "full output" and a gentle increase of RPM should show increasing charge on the ammeter.

This will show that you have power to the field, that the alternator is good, and that the charging lead into the interior, through the ammeter, and back out to the battery is OK

 

[williaml]

Well I was speaking with a guy I know and he recommended I change the vault regulator. I told him I didn't touch the voltage regulator and it worked before I changed the alternator. He was adamit to change it. I went and purchased and installed the voltage regulator. The gauge went from discharge to charge. I don't know how it could have just gone bad when it was fine before the new alternator.
Thanks for all your help !!!!!!

 

[67Dart273]

Well I was speaking with a guy I know and he recommended I change the vault regulator. I told him I didn't touch the voltage regulator and it worked before I changed the alternator. He was adamit to change it. I went and purchased and installed the voltage regulator. The gauge went from discharge to charge. I don't know how it could have just gone bad when it was fine before the new alternator.
Thanks for all your help !!!!!!

This is called "throwing parts at the problem." What all the tests are about is to see if you NEED a regulator or not. You picked the "good roll."

If this had been an engine computer, you'd now be out a few hundred bucks, whether it fixed the trouble or not.

But ---- happy you got it working ------