I HAVE CHANGED THE BATTERY, ALTERNATOR, AND THE VOLTAGE REGULATOR ON THIS CAR AND STILL THE BATTERY WOULD NOT CHARGE UP. ON THE OTHER HAND WHEN THE ENGINE IS ON WHEN i DISCONNECT THE BATTERY THE CAR WOULD DIE INSTANTLY. I HOPE YOU CAN HELP ME ON THIS.
Measure the voltage at the B+ of the alternator and the battery positive terminal post with the engine running. If they are both 12 volts or less your alternator is not working. If the two are different i.e. battery at <12 and alternator at >13 then you have a problem with the circuit from the alternator B+ to the positive battery terminal. Go across each connection with the DVM leads looking for the presence of a voltage drop i.e. alternator B+ post to wire terminal, wire terminal to actual alternator wire, alternator wire to next connection, etc. finally check the battery wire to battery post. If any connection shows a voltage drop of more than 0.2 volts clean up that connection. If you have an amp meter on the dash don’t forget to check the connections to that and look for the voltage drop across the amp meter itself.
The voltage regulator should be controlling the voltage to the field coil of the alternator. Check for voltage on the field terminal of the alternator, it there isn’t anything there, then the alternator cannot put out a charge. The wire from the voltage regulator may be broken.
Thank you, I’ll try this.
you mention changing all these parts. Why? What was the original symptom? As keith mentioned suspect the wiring itself, since the car is so old. Cracked insulation, broken wiring inside the insulation, kinked wires, and (dont shoot me!) loose/ corroded crimped on connectors from other repairs may contribute to this too.
I think this is the first year Ford used alternators…If it were mine, I would get rid of ALL that obsolete stuff and install an aftermarket single-wire alternator with a built-in regulator…