Charging issue

[1mean7Ddart]

Having trouble figuring out why my alternator is not charging... I'm almost certain it's has some thing to do with the field wires. I have no power to both blue and green wires... Checked the VR and I got no power there either!
Any idea what can be going wrong?

 

[67Dart273]

Please detail EXACTLY how you checked for power

Key on? engine running?

With key on, engine off, and all wiring hooked up "as per normal" you should have

1--same as battery at the blue alternator field terminal. Again, all wiring hooked up, "backprobe" the terminal. If no voltage, you have a problem in the under--hood ignition wiring. That blue branches off from the "ignition run" dark blue, which supplies ignition system, regulator "I" terminal, the blue field, and a couple other components in some models

2--Green should be a low reading. For a quick test, unhook the green field wire, use a grounded clip lead and ground that disconnected alternator terminal. You should see a small spark in subdued light, indicating current draw. REcheck that you still have "same as battery" on the blue

3--Start the engine, watch the ammeter, and see if the ammeter goes up to charge. If not, crank engine speed up to simulate "low to medium" cruise RPM, and check voltage both at battery and at alternator output post. If battery is below 13.5, and alternator post is about the same, alternator is not charging. If battery is low, but alternator stud is substantially higher, then you have an open in the charging line/ alternator circuit path to the battery

 

[1mean7Ddart]

I have no power to the blue at all times

 

[TrailBeast]

I have no power to the blue at all times

You saw the part where he said the blue wire should have ign power to it?
There's your clue.

Find out where the blue wire looses connection to the rest of the system.
If it were me, and my car I would give that blue wire power and see what it does, and then go from there.

 

[BillGrissom]

Ditto. For those who run into a problem with the alternator showing "discharge" on a road trip, disconnect both field terminals and run a jumper wire from one to BATT+ and ground the other. You should see a healthy "charge" on the ammeter then, which will get you home. Don't keep it charging >30 min or you may start dissociating the water in your battery (making O2 & H2 which are explosive). Use a $4 Harbor Freight cigarette plug monitor to keep tabs on the charging. Disconnect the BATT+ wire when you stop or you will slowly discharge the battery. You do carry alligator jumper wires in your trunk I hope. I do in all my cars, plus a multimeter, spare hoses, belts, ...

 

[67Dart273]

I have no power to the blue at all times

You saw the part where he said the blue wire should have ign power to it?
There's your clue.

Find out where the blue wire looses connection to the rest of the system.
If it were me, and my car I would give that blue wire power and see what it does, and then go from there.

Ditto. .

The blue "ignition run" or as Ma calls it "IGN 1" comes out of the bulkhead and at some point branches off and feeds

the switch side of the ballast resistor

the regulator "I" (ign) terminal

the blue alternator field wire

On cars which have them, the idle solenoid, and the distributor retard solenoid. On some cars, other smog doo dads.