Wiring Diagram needed

[ThunderBaker]

I am in the process of generator-to-alternator conversion. I got the alternator from a 1988 Ford Crown Vic 5 liter. It is a 100 amp alternator. It seemed straight forward until I started it and the generator light stayed on. After I put bearings and brushes in the alternator; I had it tested and it tested good. I can't find a 1988 wiring diagram on-line. Can anyone help?

Thanks
Marshall

[ThunderBaker]

Wiring Diagram

I forgot to mention,the alternator has an external regulator.
Thanks,
Marshall

[jopizz]

Do you have the I terminal on the voltage regulator going to the small yellow/black wire that goes to your indicator light.

John

[ThunderBaker]

Wiring diagram

Yes the existing yellow/black goes to I.The S goes to the
alt.STA.The F goes to the alt.F.The A goes to the alt.
Batt.I read battery voltage with the I wire off the voltage regulator.I read 14.2 with the I wire on the voltage regulator and the GEN light on.

[jopizz]

It sounds like you have everything wired correctly. I assume you ran a ground wire from the alternator to the voltage regulator case. Obviously the alternator and voltage regulator are working if you have 14 volts. I've had quite a few bad voltage regulators right out of the box so that's a possibility. Try putting a bulb directly on the I terminal and battery and see what happens.

By the way did you run a heavy wire from the Alternator to the starter solenoid. A 6 gauge wire is recommended but I used a 4 gauge starter cable with a 100 amp fuse. A fuse is a must when you have an alternator.

John

[simplyconnected]

I like this one because of its simplicity:


BTW, the resistor is important. If you burn out your GEN LIGHT, the alt will still charge. - Dave

[ThunderBaker]

Wiring Diagram

John and Dave,

Thanks for the info. I went to the boneyard yesterday and took a voltage reg. from a '91 Crown Vic. I put it on this morning and everything works! The only thing left to do is to install the 500 ohm resistor and decide what size fuse/link to install on this 100 amp alternator.

I'll go to O'Reilly's tomorrow to try to return what I believe is a defective regulator.

Thanks,
Marshall

[simplyconnected]

Glad to hear you got it going, Marshall.
The fuse is there to guard against a shorted diode in your alternator. If a diode shorts, the battery will try to unload everything it has through your alternator to ground, in very short order.

I would use #6AWG copper stranded wire on your alternator and fuse it with a 150amps Mega Fuse (not a breaker).

If the fuse blows it will allow you to safely start and run your car to a garage. - Dave