i am having charging system problems .i have replaced the regulator twice ,and the alternator three times and had them tested they show up good i have also replaced all the wiring in the charging system and checked it for continuity they all show up as good .and also bought a new battery.but its still not charging. any suggestions would be really helpful at this point i dont know what else to look for thanks.

What's the voltage at the large red wire on the alternator when the car is running? What's the voltage at the battery + cable when the car is running? Check both at idle and maybe 1500 rpm. Hopefully you have a meter, you won't be able to troubleshoot this properly without one. Post the results, if you have a meter then there are more tests that can be done to isolate the problem.

What makes you say it's a charging system problem? Does the battery go dead while driving? Does it go dead while parked, not in use?

If you are 100% sure the wiring is correct, the alternator and VR (voltage regulator) are good, checK terminal 3 at the VR. This is the sense wire for the VR and should have 12 volts, if no voltage, the fusible link may be blown. Below is a post from another member (Peter F) on troubleshooting externally regulated charging systems.
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I dug this out from before, hopefully it help. If not, just post or send me your questions.

I'll try to provide a simplified explanation of how the externally regulated alternator and regulator work here. This explanation starts from a parked car with engine off state.

The regulator brown #4 wire is connected through the light bulb to 12V whenever the key is in the ON position. The other end goes through a set of points in the regulator and then out the F terminal to the field winding in the alternator. So some current begins flowing in the field winding from this connection. The little bit of current flowing produces a weak magnet field in the alternator and also lights the bulb.

When you then start the car, the weak magnetic field from above begins rotating which makes the alternator producing a little bit of voltage. This voltage is fed from the alternator to the regulator on the white regulator #2 wire. This wire connects to a coil in the regulator and turns on a contact when the voltage goes above 3.2V.

Once the contact turns on in the regulator the #3 and #4 terminals are connected together. Terminal #3 is battery power so this puts battery power on both sides of the bulb and turns it off. This means the brown #4 wire should go to +12V. Also, this connects the field terminal right to battery power but still going through the points.

When the battery voltage goes above a set level, the F terminal is disconnected from the battery power by the points I kept mentioning. Then the voltage drops and the points close again. This on-off cycling happens rapidly and is how the voltage gets regulated.

From the above (KOEO = key on engine off and KOER = key on engine running).
F or #1 terminal (field) - KOEO = #4 slight voltage, KOER = 9-12V typically
#2 terminal (sense) - KOEO = 0V, KOER = >3.2V
#3 terminal (Battery) - KOEO = 12V, KOER = 12V
#4 terminal (light) - KOEO = F slight voltage, KOER = 12V

By 12V above I mean battery voltage, which may be 12V when engine is off but could be up to 14.5V when engine is running.

Check the light: Ground the brown #4 terminal wire at the regulator. When grounded the light should come on. If you don't have a light then skip this test. Test this with the connector off the regulator.

Checking the alternator: Jumper the blue wire F terminal to the battery post on the back. This should make it easily crank out 16+ volts. Next, connect a troublelight between the battery post and the F terminal. The light should come on and you should measure > 3.2V at the other alternator terminal. If it passes these tests, then it's in the regulator or wiring.

Checking the wiring: At the regulator connector jumper the brown light wire (#4) to the F terminal (#1) and you should be able to measure >3.2 volts on the other alternator terminal or terminal #2 of the regulator connector. If these tests pass, it is in your regulator.

When doing these tests, make sure you turn off or pull the fuses for any added electronics that you can. The alternator test can produce enough voltage to damage stuff.

Peter

thanks for writing me back .and yes i have a meter and i have checked both the red wire and and at the +side while its running they show 12.43to 12.45 .

(continue of message before) it will go dead when parked but at a slow but very slow drain about a couple of days.

Well, 12.4v is about what you'll see from a fully charged battery. When running you should see around 14.5v. So yes it does sound like a charging problem. The fact that it goes dead after few days may be related so tackle the charging problem and you might fix both problems. Use the method Greg (undee70ss) posted to see what's wrong. If you find something wrong while doing that and have more questions post back with the readings you got and someone can help.

(continue of message before) it will go dead when parked but at a slow but very slow drain about a couple of days.
To test for the drain, disconnect any clocks and radio with memory, with the car off disconnect a battery cable and connect a test light between the cable and the battery, with a drain the light will be lit. You need to make the light go out to find the drain. Disconnect things one at a time till the light goes out. First disconnect the alternator and voltage regulator plug, then fuses at the fuse box. Post back with results.

hey sorry it took so long too write back my car is 2.5 hrs away from my house .had too move it because neibors complained it was too loud.anyway i checked out everything you suggested and used the article as a guideline and this is what my car is showing at the regulator.on the blue wire while runningit shows 6.3vlts,and the white shows nothing0.0vlts.the orange shows 12.45/battery voltage.,and the brown shows 0.3vlts.

also it does not change any of the voltage measurements while off and in park.they are the same. and now it drains as you drive it .?im usually good with troubleshooting wirirng issues but this won is driving me nuts.

hey sorry it took so long too write back my car is 2.5 hrs away from my house .had too move it because neighbors complained it was too loud.anyway I would never move my car 2.5 hrs away because of neighbors, anyway


i checked out everything you suggested and used the article as a guideline and this is what my car is showing at the regulator.on the blue wire while running it shows 6.3vlts,Not sure how possible because the voltage on the brown is so low, unless the alternator is producing it. since you replaced all the wiring, you have the blue connected to the "F" terminal at the alternator, and "F" or terminal 1 at the regulator right?



and the white shows nothing0.0vlts.
Without voltage on the blue coming from the regulator there will be no voltage here. You have the white connected to the "R" terminal at the alternator, terminal 2 at the regulator right?


the orange shows 12.45/battery voltage.,
This is good


and the brown shows 0.3vlts.
Not good, this wire powers the charging system, and power comes from the IGN switch. Do you have a light or gauges? Did you do this test,
Check the light: Ground the brown #4 terminal wire at the regulator. When grounded the light should come on. If you don't have a light then skip this test. Test this with the connector off the regulator.

For another test you can remove the brown from the regulator, run a wire from the battery (put a fuse close to the battery for safety sake) to a lamp, ( a old side marker lamp will do) to the #4 terminal at the regulator. With the car not running the lamp will be on, when car is started lamp should go out. Check the voltage at the battery with the car running at a fast idle, should be 14+ volts. Your problem is with the brown, it has to have battery voltage.

my car has idiot lights in dash and the gen light stays on most of the time .but every once in a while it will go out for a few seconds but it comes right back on ,and does not flicker at all while running.also the regulator does not kick up the voltage at all .you dont here it click to close the contact points. but if i jump the blue wire with the orange wire it kicks the voltage up around 13.6 to 13.8 or so and stablizes .and yes i know it should because its getting direct battery voltage by jumping it that way.just thought id add that in. thanks

my car has idiot lights in dash and the gen light stays on most of the time .but every once in a while it will go out for a few seconds but it comes right back on ,and does not flicker at all while running.also the regulator does not kick up the voltage at all .you don't here it click to close the contact points.
If the Gen light is on, the brown has to have more than .3 volts unless its grounded further upstream. Did you disconnect the regulator plug or leave it plugged in to get that reading? With car off and key on, disconnect regulator plug, does GEN light go out? Also make sure the regulator case is has a good ground.


but if i jump the blue wire with the orange wire it kicks the voltage up around 13.6 to 13.8 or so and stabilizes .and yes i know it should because its getting direct battery voltage by jumping it that way.just thought id add that in. thanks This is the same as field testing, alternator should be putting out 16+ volts with car at fast idle. If not alternator may be bad.

If you are 100% sure the wiring is correct, the alternator and VR (voltage regulator) are good, checK terminal 3 at the VR. This is the sense wire for the VR and should have 12 volts, if no voltage, the fusible link may be blown. Below is a post from another member (Peter F) on troubleshooting externally regulated charging systems.
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Undee70SS, I have been following this thread as well because I'm having charging problems as well.

Here are my results: 70 396 air car w/63 amp alt w/ext regulator. Rebuilt alt, new regulator.
All values taken at the VR terminal with the regulator plugged into the harness.
#F=KOEO-"0" volts-KOER=4.1 volts.
#2=KOEO-"3.2 volts-KOER=12.6 volts.
#3=KOEO-12.6 volts-KOER=12.48 volts.
#4=KOEO-.03 volts-KOER="0" volts.

Could it be a blown fusible link?

Car will charge @ higher rpm's but when lights are turned on, voltage drops way back, from 14.50 or better back down to just about 12 volts, put the air on with the lights, now were in the red at about 11.50 volts or lower.

Any suggestions?

Gibby

Undee70SS, I have been following this thread as well because I'm having charging problems as well.

Here are my results: 70 396 air car w/63 amp alt w/ext regulator. Rebuilt alt, new regulator.
All values taken at the VR terminal with the regulator plugged into the harness.
#F=KOEO-"0" volts-KOER=4.1 volts.
#2=KOEO-"3.2 volts-KOER=12.6 volts.
#3=KOEO-12.6 volts-KOER=12.48 volts.
#4=KOEO-.03 volts-KOER="0" volts.

Could it be a blown fusible link?

Car will charge @ higher rpm's but when lights are turned on, voltage drops way back, from 14.50 or better back down to just about 12 volts, put the air on with the lights, now were in the red at about 11.50 volts or lower.

Any suggestions?

Gibby
Unplug wires from VR, with KOEO #4 (brown) should be 9-12volts to ground. Next check wiring, #F, a blue should go to "F" terminal at alternator, #2 a white should go to "R" terminal at alternator. Your readings seem to indicate that "F" and #2 are reversed as you should not get 12.6 volts on #2. Make sure regulator is case is grounded.