Alternator is overcharging....

[kimcrwbr1]

Make sure the grounds are all good, You have battery voltage at the alternator large connection and the voltage regulator A terminal on your schematic above and they are the same. Field and stator wires go between the alternator and the regulator check for shorts if you have the choke hooked up to the stator wire disconnect it and then look for shorts. Key on ignition goes to the I connection. The tech library undercharging system troubleshootin will help you isolate the fault. GL

 

[kimcrwbr1]

Sorry this is the one I meant.
http://www.therangerstation.com/tech_library/chargingsystem.htm

 

[Jim Oaks]

Is this a standard Ford integral-regulator alternator?

I'm kindof just guessing here, but it sounds to me like there's an open circuit in the voltage sense lead to the regulator. If this input terminal has no connection on it, the alt will then run fully-unregulated, putting out max voltage (your battery being the only thing limiting it from going higher than 16-17 volts).

Check and see if full battery voltage is present at the "A" terminal on the back of the regulator with the key on (engine not running). IIRC, that is where the regulator senses the voltage.

Also, make sure nothing is grounding against the "F" terminal (it should read the same voltage as the "A terminal with the key OFF).

I have voltage at 'A' with the key off.

 

[Jim Oaks]

Ok, I think I figured it out.

I had moved the voltage regulator to the plastic inner liner and it wasn't grounded. I ran a wire from one of its mounting bolts to the body and now I'm putting out 14 volts.

 

[4x4junkie]

That would definitely do it if the regulator gets it's ground through the housing.

I'd probably ground it to the engine rather than the body (more direct return path back to the alt itself, which should help it regulate more consistently as electrical demands vary). Assuming this is how it was factory... If not, then disregard.

 

[PaulBennett]

The alternator has 2 coils. One coil produces the voltage to charge the battery. The other coil determines voltage output with a regulator which feeds it a variable volage which regulating the magnetic circuit between the two coils and to establish desired voltage output. The regulator gets its knowledge from a feedback circuit, essentially a component connected to the battery.

So, between the regulator and alternator coil is a calibrated component which establishes the alternators voltage output. In most cars, that component is the 'Alt' warning light. In other vehicles it's the alternator meter shunt. Alternators are not fed the entire current but a representative postion provided by a resistive shunt. Removing either feedback circuit and connecting their wires together puts the alternator in full overcharge mode and smoke is likely soon afterward.

Whatever you stripped out must be returned exactly unless you intend changing to a different regulator circuit.

This has nothing to do with grounds...replace the shunt if not the meter and it sets the voltage level for the regulator. !!