started my truck(94 turbo idi)and noticed my battery light was on.get out the voltmeter and i got 14.4 volts at battery.WTF!turn on headlights blower motor and voltage drops to 12.9 at idle,rev motor to 1500 rpm and jumps back to 14.4.okay do a little testing according to posts i found on this forum and find that i have no voltage at the stator terminal on the alternator.when i unplug the the one wire connector then i read 6.5 volts or so with engine running.plug stator connector back on zero.so when i hook the stator into the voltage regulator something happens.what is causing this<bad voltage reg. or the alternator?the alternator is relatively new. thanks in advance for any help.

 

Not sure I follow your description, so will tell what I can figure out. Heavy Black/orange wire is output to battery- 14.4 volts normal. single wire plug out of stator is the switch wire voltage back to the regulator section, tapped off of one of three sections of the stator 6V normal. The yelow/white wire is output/battery voltage back to the regulator. The charge light is powered off of the ignition switch, if the alternator is not charging, the regulator grounds the light green/ red wire internally, illumination the charge light. Once power is being produced the regulator lg/r wire also has full voltage to both sides of the indicator light, so no current flows and the light stays off. Sounds like a section of your regulator is on the way out

 

fixed it,the voltage regulator must have been shorting out the signal from the stator.

 

Regulator? On a 94? I thought they were part of the alternator?

 

Yep, screws into the back of the alternator.

 

fyi , the battery lamp . on vehicles equipped with a voltmeter have a resistor across the bulb leads and if the resistor fails it will also turn the light on