now i have a charging problem. can't figure it out. have a new alt. and two regulators. one regulator if hooked up with car running will read no volts at field side of regulator or alt. other regulator when hooked up and running will read 11 or so volts at field side of regulator and alt. less than the battery itself(12.2) is reading. i assume the first regulator is bad, and the alt. checked out ok at the store, so is the second regulator also bad? the alt. should read 13 or 14 correct at the field and at the field side of vr. either way i am not getting a charge. any help would be appreciated.

what car?
what kind of vr?
what kind of alt?

duel field, single field?

dual field one might read 12 volts, but the other should not.

single field, it should not read 12 volts.

for the 0 volts, where are you taking that measurment?

sorry, single field, 66 charger, solid state vr. taking readings at the field side of alt and the field side of vr with a volt meter. have battery power at alt battery stud and battery with car off, no where else. with car running, i have 12.2 or so at battery, alt battery stud, ignition side of vr., ballast resister. then 11 or so volts at both alt. and vr. field connections with car running. if i should be getting like 13 or 14 volts at both fields with car running and i'm getting 11 does that mean the vr. is bad? had the auto store check the alt and they said it was good.

if you are sure you are measuring the field side, then yes, the VR is bad. it shouldn't be 12 volts at the field, only the sensing line.
I remember it was like 2 volts or so at the field for me last time I checked.

now i'm kinda confused, what do you mean by 2 volts or so at the field for you. i thought the field should push like around 14.5 volts. shouldn't the field always be more volts than the battery volts?

The stock regulator in the early setups is nothing more than a switch, on/off/on/off etc. It essentially pulse width modulates the alternator. These are adjustable, look in the FSM to see how to adjust them.

I don't know how the aftermarket electronic version does it's thing, that might be what Andrew is talking about.

The "bad" VR probably has a blown fusible link inside. It is fixable.

i realize that the vr is just an on off switch but i also thought the the alt is always giving its full power all the time and the vr decides how much of that the rest of the system needs. so i should be getting a full 14.5 volts or so at the field at all times, correct? if not the vr is bad?

you are confused.
the sensing line should get 12 volts or whatever you get at the battery, based on good grounds to the box and a good clean line for power.

out put of the vr is not going to be the same. or why would you need a voltage reg?

it converts the voltage to another voltage for the alternator to generate power against.
it changes the field strength of the alternator by varing the voltage it sends.

IF the alt is good & the reg is good all you need for the early system to charge is (1) switched 12V to the "ign" (blue wire) reg terminal. (2) continuity between the reg field terminal (green wire) and the alt field terminal. (3) the reg base is grounded. I'm assuming this alt only has 1 field terminal (if two (later alt) just ground one of em to alt case)

so here is were i am. with car off i have 12.2 volts at battery. i ran the car with lights, highbeams, heater, radio, brakes, and turn signal and the battery was at 11.5 or so and the field was at 10.2 and a little higher while it was switching for the turn signal. i let it idle like that for maybe 10 or so minutes, turned the car off and the battery was at like 12.1 or so. started the car 4 times in a row to see if the battery would turn it and it started everytime. one thing i do see is that i have a factory alt gauge in my cars dash cluster, and with all of the accessories on it dips to less than 1/4 of power on the gauge, giving it rpms doesn't change the alt gauge or the volts on the meter. does this make any sense? any help is appreciated. JZ

Take the field wires (both) off of the reg. Jump fire from the alt "batt" stud to the male alt field terminal. Start car (3 seconds only just long enough to take a voltage reading) with all bulbs/headlights/accessories off. If charging (13.8+) the alt is good & the other end of its' field circuit (alt case) has continuity to ground/batt neg). Stop the eng & replace the blue wire on the reg. You stated earlier that you have switched 12V to that blue wire "ign" side of the reg. Run a jumper from the "field" green wire side of the reg to the alt field male terminal & restart it & if it charges (3 seconds max) then green wire you bypassed has an open. If it dont charge then the new reg is bad (or not grounded & I think we checked that).

Like RapidRobert says run the jumper across the volt reg ign and field temnals and it should get full ouput.
The old stock mechanical voltage reg did vary the voltage at the field as it has resisters in it to drop field voltage when it sees enough volts sensed from the ign wire at the reg. If voltage gets to high it would open or close the contacts in the reg to put field volts thru a rsister to control output. The more load on the electrical system the more volts you should see at the field wire on the old mechanical systems. Ron

I just had a similar problem on my GTX. Everything checked good but alt did not put out voltage. What fixed my problem was grounding the alt to the car. I used a 10 gauge wire and grounded the alt to a fuel pump attach bolt.

well let me just tell you this. i had everything hooked up ran it at idle for 10 minutes with everything on, alt gauge was a 1/4 but everything seemed ok. drove it for a while with lights on so i'd get an extra draw, alt gauge was at 1/4 no movement on it at any rpms. i am getting a reading at the field the whole time (it's always less than what the battery reads). this morning decide since i'm not draining the battery and nothings dying that i'll drive it to work. nothing changes until i'm almost out of my neighborhood, then my alt gauge spikes all the way to full power and it's rpm sensitive. limp it home so it doesn't stay full on power. get home and start it, exactly the same as before, no movement at the alt gauge and no movement at any rpms. i'm so sick of this. battery checks ok, alt checks ok, two vr's one which is a year old doesn't work anymore and who knows about the other which is brand new. i have replaced any and every wire that was suspect over the last 2 years, in dash and engine compartment. i've bypassed the bulkhead connection with my main power wires just to be sure. ran an extra ground wire from the alt just in case. no wires at this point are melting or seemed to be problematic. yet every year i have the same charging troubles. is there anyway i can upgrade this system or anything so i can be done with this headache? JZ

your new vr is broken.
it should be inversly proprtionaly to the battery voltage on the output.

http://www.autoshop101.com/trainmodules/alternator/alt131.html

it is regulating the magnetic field.
if it sees a high voltage at the battery, it should reduce the voltage at the output to lower the magnetic charge.

if it sees low voltage at the battery, it should increase the field strength by upping the voltage.

Thanks for all the help guys. Think I'm gonna try one more vr, probably just a good old fashioned mechanical one and take it from there. I appreciate all of your feedback, and I keep you posted. JZ

ok i changed the vr, i bought a mechanical one and i'm still nowhere. the only thing that isn't brand new is the battery, but i had it tested and it checked ok, marginal but ok with no bad cell. i'm just kinda stuck. before this whole charging incident my alt gauge used to read a draw when something electrical was used and then read that it was being compensated for by returning to around the center. now it just stays low. all the time low. rpms up it's low. all i'm doing is throwing money at parts that don't correct the problem.