Alternator help

[thll]

Hello I am currently repairing a friends 95 ford explorer and here is the break down. The alternator is not charging the battery. The alternator and battery are new. Continuity tested the line from the alternator to the solenoid to make sure the inner fuse wasn't blown. Continuity tested the three prongs from the alternator to a grey plug next to the fuse box, oh and tested all the fuses.

I think this is a excite issue? The three prongs on the alternator that go to the grey plug need to do something right? Right now it wont charge with the grey plug plugged in or not plugged in.. My guess it has something to do with the grey plug.. what is it? and how do I test it?

 

[thll]

I suppose some power has to go to the alternator to excite it right? I unplugged the 3 prong plug from the alternator to see if there is power coming from the plug. I grounded my meter and turned the car on and the yellow plug had .06 millamps and green had nothing. Of course the black wire is ground

 

[2000StreetRod]

1995 charging diagram

The 1995 Explorer charging diagram is shown below.

Read the voltages to ground with your meter instead of current.
The C121 Yellow/White stripe wire should have battery voltage at all times. If not, check fuse 17 (15 amps) in the power distribution box.
The C121 Light green/Red stripe wire should have battery voltage when the ignition switch is in Run or Start. If not check fuse 15 (15 amps) in the interior fuse panel and fuse 1 (60 amps) in the power distribution box.

 

[thll]

Thanks for the reply, 12volts at yellow and 12volts at green when on. So this means bad alternator?

 

[2000StreetRod]

fusible link?

If the old alternator shorted out the fusible link could be blown. Check for battery voltage on C122 Black/orange wire.

 

[thll]

Check that and its good. Also the black/white wire also has a voltage? Thought that would be a ground

 

[2000StreetRod]

take it back

I suggest that you take it back to where you bought it and have them test it.