How many volts should be coming off the FLD terminal on the Voltage Regulator?

[Corellian Corvette]

I recently read the Hot Rod "We'll Fix It" article that was chasing down some electrical gremlins on a '69 charger, and I decided to take a look at my system just in case.

I have a 68 Charger with AC, 383 and basically stock wiring (I did bypass the resistor block to run full voltage to my MSD distributor)

I am running a 60-amp dual-pulley Alternator with the 2 field plugs. One of the FLD plugs is grounded to the housing, and the other goes to a stock-appearing electronic voltage regulator (I don't remember where I got it - it was one of the specialty shops, not NAPA). It looks a lot like this one

http://www.holidays.net/store/Mopar-Voltage-Regulator---Electronic-Solid-State-With-Correct-Appearance-_181096388968.html

As I was testing out the voltage across the battery, coil, etc. everything appears good. I'm getting about 14.2 volts with very little drop. If I disconnect the FLD wire at the alternator, voltage drops down to 12v across the system. So I think that means the regulator is working.

However, when I measure voltage JUST at the FLD terminal (at both the regulator and the coil), it's fluctuating between 7.5 and 8v.

One thing the Hot Rod article said was something about using an "electronic voltage regulator that was incorrect" and also they talked about adjusting the points to get "a full 13.7V at the FLD terminal.

Is it typical to have only ~8v coming off the green FLD wire? Would this explain some of the 'jumpiness' of the AMP guage?

Thanks!

[Pete in NH]

Hi,


With 14.2 volts at the battery that drops to 12 when you disconnect the field of the alternator, I would say your system is operating normally. The regulator will constantly adjust its output to the field to maintain the 14.2 volts at the battery. That is why you see the field voltage vary between 7.5 and 8 volts. It's not the voltage on the field but current through the field that matters as the field creates a magnetic field to drive the stator windings of the alternator. The varying field voltage is only an indication that the field current is changing as it should. Again, everything seems to be operating as it should. so, nothing to worry about. Hope this helps. I'm not sure where the magazine article got their information from.