Charging System Failure

[erik70rt]

Thanks!  I'll check it when I get home tonight.

[erik70rt]

Thanks everyone for your help/input!  Turns out the problem was when I installed the new engine harness, the 12 ga wire for the alternator pushed out of the connector and therefore wasn't making contact with the main harness.  I pushed it in and TA DA!!!!  Fixed. 

[Rev-It-Up]

Thanks everyone for your help/input!  Turns out the problem was when I installed the new engine harness, the 12 ga wire for the alternator pushed out of the connector and therefore wasn't making contact with the main harness.  I pushed it in and TA DA!!!!  Fixed.

Gotta love easy fixes!   

[73440]

Having charging problems .
@1wildr/t , I am using your info on the voltages and wiring.
Have 12v constant at output bolt, 12v on blue wire when key on, replaced VR and scraped paint off firewall and VR, grounded the green wire at the VR and no change in battery voltage.
Question is , if I run the 10 guage wire from alt output to battery starter relay and it starts charging , can the wire be left in place ? Is that wire a part of the ammeter bypass ?

[TelisSE440]

Having charging problems .
@1wildr/t , I am using your info on the voltages and wiring.
Have 12v constant at output bolt, 12v on blue wire when key on, replaced VR and scraped paint off firewall and VR, grounded the green wire at the VR and no change in battery voltage.
Question is , if I run the 10 guage wire from alt output to battery starter relay and it starts charging , can the wire be left in place ? Is that wire a part of the ammeter bypass ?

If the alternator output, has 12v current, then this is the battery's current, check with your voltmeter and you'll see that they are pretty much the same (unless there is a huge resistance). The alternator has a black wire which goes into the firewall via bulkhead connector, attaches to the one side of the ammeter, while the other side has a red wire which goes out of the firewall,via bulkhead connector and to the battery. WildR/T was explaining that the aforementioned electrical connection was cut (which yours isn't, you have 12v in the alternator), so he said to bypass all this connection with a wire from the battery directly to the output stud of the alternator. You'll see no difference in the problem if you install it, but do install a heavy gauge wire when all this is done because it is the ammeter/firewall bypass.
Now unplug the green wire from the alternator, make sure that both the output stud and blue wire (open ignition) have 12v current, Have the voltmeter to check battery voltage at all times, start the engine and connect a wire from the bare probe of the alternator (the one where the green wire hooked into) to a any ground source nearby, preferably the engine steel surface, if the alternator is working then the voltage should go to the extreme. Be careful not to let the voltage go over 15 and under any circumstances over 16v. Disconnect immediately... If voltage doesn't climb up then it is the alternator's malfunction, or there is a very poor ground of the alternator to the engine. Hope i helped.

[Dakota]

Gotta love easy fixes!   

Gotta love the quality guidance too!

[73440]

Thank you@TelisSE440.will give that a try.
And unfortunately the spare alternator I bought three years ago is not a squareback so have to buy another if needed.

[73440]

Checked, have battery voltage at both output stud and field stud with key on, no change in battery voltage when started and running wire from alt green stud to engine ground.
Time to try new alternator, and I will put a 12 guage fusible link on the 10 guage wire from alt output stud to battery post on starter relay, forgot to buy today .

[TelisSE440]

Sorry to hear, hope you sort it out soon...

[73440]

Pulled the VR  connector and scraped on the connection, replaced it and all same , not charging.
Removed the alternator and spun the pulley and noticed it have very little drag as opposed to the new alternator that when spinning the pulley had much more drag.
Installed the new alternator and now charging at 14 volts !
Thank you for all the electrical tips, also bought a 14 guage fusible link to install on the 10 guage alt bat output to battery post on starter relay.

[TelisSE440]

Glad everything worked out 

[73440]

Gonna take a test ride and see if the higher voltage may help a little running problem, never know, always  need good spark, fuel and compression.
Even going thru the troubleshooting process helps in learning about the electrical system.
And thanks to @cudabob496 about the AT-205 stop leak the PS still has not leaked in a week ! Usually dry overnight.