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Alternator not charging

5K views 11 replies 7 participants last post by  EOD Guy 
#1 ·
Hi all, this is my first time posting, the alternator isn't charging on my 67 Camaro. I have an optima red top battery that is known good as well as a new voltage regulator and a remanufactured alternator. I went through all the wiring to make sure there weren't any loose or corroded connections, I even went so far as to unwrap the wiring harness to expose and check the factory soldered splice. With the car running I am reading 12v at the battery , 12v at battery post on the alternator, 12v at the F(blue) terminal on the regulator, 0v at the #2(white) terminal, 12v at the #3(orange) terminal and 7v at the #4(brown) terminal. I think I should be reading 12v from the ignition switch on the brown wire at the regulator. If anyone has any information they could share it would be greatly appreciated. Thanks.:)
 
#3 · (Edited)
12v at the F(blue) terminal on the regulator,
0v at the #2(white) terminal,
12v at the #3(orange) terminal and
7v at the #4(brown) terminal.

F terminal is your exciter wire and it looks like it's providiing 12v to the alt to tell it to produce juice.

#2 or white is your sense wire and it tells the alt to produce more or less juice depending on the demands of your elec system.

#3 or orange (also your fuseable link) is the supply to the fusebox

#4 or brown is the supply from the ing. I don't remember if it was 12 volts or 9...... but I think it was 12.

Sounds like the alt is bad, as suggested above get it checked out, just because it's new doesn't mean it's good.

Some sound advice....... switch over to an internal regulated alt, super easy to do and it's very un-do-able should you decide to go back stock. I did it..... no more dim lights, heater fan and all the electrical Gremlins dissappeared.

Basicly you disconnect the wires from the external regulator

Jump F or the blue wire to #4 or the brown wire,
Jump #2 or white to #3 or red wire.
Add a new 10 gauge wire from the factory junction post (behind the battery on the radiator support) over to the horn relay to handle the increased output from the new alt....... that's it
 

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#7 ·
I don't know if a one wire is the answer. I put a new Powermaster one wire on the 33 and it has less than 2000 miles on it and it os overcharging. I am getting over 18 volts at the alt. I don't kow it can be fixed or it is another new one. I spent the money on what I thought was a top of the line and it has just caused problems.
 
#8 ·
Don't go to a One-Wire set-up, ...they don't sense system requirements to provide the correct voltage. Lots of folks have headaches related to them.

Use a stock 3-Wire Internal Regulated alternator (Delco 10Si) and follow the wiring diagram posted by EOD Guy in his post. It makes a good set-up, and bolts right on to the stock brackets in place of the old External Regulated stock alternator.
 
#9 ·
Not a fan of the one wire...... it works just as well as a three wire at higher RPMs, it's at idle or slow cruse'in speeds that the one wire doesn't perform as well, as mentioned above it doesn't get a true sense of the elec demand on the system...... because it's sense wire is about 3-4 inches long.....Gm orig took advantage of the long run from the alt over to the horn relay, factory splice, and had a true sense of the demand etc.......

I went with a three wire chromed.....less than $100 on ebay
 
#11 ·
Problem solved, charging at a strong 14 volts. When I changed the plug on the back of the alternator I spliced the wires color for color but after further investigation I realized the blue and white wires were reversed, the blue needs to go to the right (F) terminal and the white needs to go to the left (R) terminal. It was easy to switch, just depress the tang inside the plug with a small screw driver and the terminal will pull right out of the plastic plug, also I had to adjust the alignment and squeeze the terminals down to insure a secure connection. Thanks to everyone that helped out.:thumbup:
 
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