3G not charging, alternator is good, few questions.

[1993SSP]

The 3G is still no charging, took the alternator off and it tested good, here is what I did when I installed it, if I don't have something hooked up right please let me know

I removed the old alternator, I plugged in the smaller 3 wire connector back into the 3G alternator, on the 3G unit I spliced the seperate blk/white wire into the blk/white (center wire) on original plug. I ran new 4 Ga. wire with 140 amp breaker inline from the alternator to the battery side on the solenoid. The other plug that came from the stock 75a alternator I simply taped up to keep dirt out of it and did nothing with it.

Am I missing something??? When the alternator is on the car it is not charging.

 

[LiquidGT]

If your not using the stock harness then your not using the hidden regulator wire in the within the harness, its the yellow/white wire on the regulator and it has its own fuse link.
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

-You need to either use the stock harness along with the 4ga, (but I always wondered about the CB and fuse link not blowing at the same time.)

-Or you could run your own regulator wire to the starter solenoid, someone on here said that it has a 20 amp fuse on the 94-95 cars. I also on The Corral I saw someone who pulled this wire out of a Continental with a 3G and it had the proper fuse link on it.

- Also I've seen an aftermarket 3G regulator conversion harness that just jumped the yellow wire to the power output on the alt. (I'm not sure if thats a proper way to do it.)

Lets see what the others have to say about your best option.

 

[HISSIN50]

Check your regulator wiring.

A should show battery voltage.
I should show over 1 volt with the car idling
S should be about 1/2 battery voltage.

Obviously be sure the charge cable's fuse didn't blow.

 

[1993SSP]

If your not using the stock harness then your not using the hidden regulator wire in the within the harness, its the yellow/white wire on the regulator and it has its own fuse link.
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

-You need to either use the stock harness along with the 4ga, (but I always wondered about the CB and fuse link not blowing at the same time.)

-Or you could run your own regulator wire to the starter solenoid, someone on here said that it has a 20 amp fuse on the 94-95 cars. I also on The Corral I saw someone who pulled this wire out of a Continental with a 3G and it had the proper fuse link on it.

- Also I've seen an aftermarket 3G regulator conversion harness that just jumped the yellow wire to the power output on the alt. (I'm not sure if thats a proper way to do it.)


Do you mean the stock harness from a car that originally came with a 3G on it?? I am putting this on a 89 model mustang.

Lets see what the others have to say about your best option.

Do you mean the stock harness from a car that originally came with a 3G on it?? I am putting this on a 89 model mustang.

 

[jrichker]

Here's how it is supposed to be wired...

Old alternator power plug

Rear view of 3G alternator

Starter solenoid wiring 86-91 5.0 Mustangs with standard starter

Starter solenoid wiring 92-93 5.0 Mustangs with mini starter

Any car that has a 3G or high output current alternator needs
a 4 gauge ground wire running from the block to the chassis
ground where the battery pigtail ground connects.
The 3G has a 130 amp capacity, so you wire the power side
with 4 gauge wire. It stands to reason that the ground side
handles just a much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery & alternator

Picture courtesy timewarped1972

 

[1993SSP]

Thanks Jrichker, got it all lined out, though it is now charging fine with the white/blk jumped over to the original 3 wire plug you show with no changes, will this be fine??

The plug that has the 2 org/blk wires and the 1 wht/blk was simply taped up and left alone.

 

[jrichker]

Thanks Jrichker, got it all lined out, though it is now charging fine with the white/blk jumped over to the original 3 wire plug you show with no changes, will this be fine??

The plug that has the 2 org/blk wires and the 1 wht/blk was simply taped up and left alone.

If it is working good, then leave it alone.

 

[1993SSP]

Ok, just making sure, I took a multimeter and checked them, they are both on the same connection. Thanks again for the help!!

 

[jwzg]

If you want to make a new harness see here for details.

 

[RB92GT]

Loop to nowhere

The reason it did not work initially is you made a loop to nowhere with the blk/white wire (you essentially connected it to itself. This wire does not go anywhere on the stock 2G except from one plug to the other, simply an external wire connecting two point on one alterator (stator). Both black/white wires on each plug are the same wire, so when you connected them it made its own little loop. Need to connect one or the other (remember, they are both the same wire, to the stator plug space on the 3G). Now, on a 6G alternator, can eliminate blk/white wire, as it is internal in the alternator.