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I recently purchased a 65 coupe with a 289. The idiot light (charging system) was on on the dash when I purchased the car. The previous owner replaced the battery, the voltage regulator, and the alternator. I assumed this must be a minor wiring problem. However, I am stumped. I started with verifing the alternator connections, which matched a diagram posted on this site earlier, then changed the alternator wiring, followed by the voltage regulator/headlight feed. This didn't correct the problem. I then took the car down to autozone and had them load test the battery and such. They said all components were fine but there was no voltage output indicating a wiring problem. I proceded to change the engine gauge feed and install a new underdash harness per the wiring diagram to no avail. I have exhausted all known causes and all other electrical works great (lights, horn, etc...). Any electrical Gurus out there with some suggestions? It would be a big shot in the ego to drive the car down to garage and pay someone else to fix the problem.
 

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At this point, I'd take it to a competent auto electrical shop and have them diagnose the problem(s) for about $50. You're right: it probably is an electrical wiring problem. Do you have the Osborne Electrical Assembly Manuals? Those are most excellent for wiring diagrams.
 

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Make sure that your headlight harness and alternator feed harness (both of which connect the alternator to the regulator and battery) are for the 65 with lights, not gauges. If at some point, someone had started to make the lights to gauges conversion (by modifying the harnesses) and simply gave up it could very well be that the circuit is either open (no charging) or grounded ( no charging and bigger problems). Make sure you are using 65 wiring diagrams and not 66! The systems are different.

If the alternator and VR are good, then the problem has to be in either the headlight harness or alternator harness.

This happened when I first got my car finished. PO had attempted to modify the headlight harness. The alternator harness was fried when I got the car so I simply replaced it with the correct one. Which promptly burned up. After replacing the headlight harness and a new alt harness the system works properly.

Good luck
 

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Could it possibly be that there is the wrong harness in there? There were 2 different wiring harness styles for a 65-one with guages-one with lights(yours). Someone could possibly have installed the wrong one or tried to upgrade to the 66 style.
 

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5 wires control the charging circuit on an early Ford;

3 wires go from the voltage regulator to the alternator.
Black/red=ground
White=S or Stator
White/black=F or Field


Unhook the battery, unplug the voltage regulator and the alternator.... With a multimeter or a continuity tester check these three wires between the alternator and voltage regulator.

A yellow wire from the starter solenoid to the voltage regulator. This carries 12V to the voltage regulator.

Unhook this yellow wire from the starter relay and check for continuity just like above.

One more wire, a large black/yellow wire from the starter solenoid to the BATT terminal of the alternator, perform a continutity test on it also.

Both the yellow wire AND the black yellow wire should be on the battery side of the starter solenoid, not the starter side. Sometimes these terminals become corroded and must be cleaned.

Check the voltage regulator for a good ground, the engine-firewall ground behind the R cylinder head.

If all the above check out as outlined, your problem is NOT wiring.
 
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