Alternator failure on Ford 1100

[LenNH]

Have a Ford 1100 (diesel). The alternator stopped charging. Are there tests I can make to see what is wrong? Have a good multimeter and am familiar
enough with charging systems to locate parts I need to work with.
Any suggestions appreciated.

 

[Mark K]

Do you know what alternator is on it? That would help. MK

 

[Mark K]

I suspect this will be your alternator plug?

If so, E is ground between the regulator and the alternator.

F is field and will be "hot" while charging

N is an output only while charging, it is typically from a diode trio. It tells the regulator that it is charging, it is sometimes used to turn off a charge indicator light on your dash, but not often with Japanese alternator systems.

Like I told the other poster about testing, a quick test would be to unplug the regulator from the alternator and power the field terminal for a few seconds and see if there is output from the N terminal, this would tell you the alternator is working. You should be careful not to power the wrong terminals of course.

Another test would be to clip a test light to bat+, then touch the tip to the N terminal with the tractor off, it should light up bright, then momentarilly power the F terminal and the light should go completely off, if it's dim, the diode trio could have a weak or damaged diode.

Powering the F terminal with straight battery power will "full field" the alternator and should only be done for a very short period, a few seconds at most.

Before I did any of these tests, I would certainly check all fuses and ignition circuits, always check the simple things first.

MK

 

[LenNH]

Very helpful. Won't get to it in this weather, but when spring comes. Thanks a lot.
LenNH