Alternator Problems Still

[95strokerPSU]

Put a charger on the battery and ended up starting the car today with a battery voltage of 12.86. As soon as I started it, I checked the alternator output and it was at 12.8. I then checked the three wires that plug into the alt. They all read the same as the alt. output except for the stator which was a little above 10v. The battery voltage read the same as the alt voltage (so problem with the battery charging). When I rev the engine up, there is no change in voltage.

Now I would be alright with 12.8v but after letting the car run for about 5 minutes, the alt output voltage starts to drop. About 2-3 minutes after that it was down to 11.98v.

Autozone tested my alt and told me everything was ok, but I don't know if I believe them. Any ideas?

Dave

 

[95strokerPSU]

ttt...need help, anyone?

 

[FORCED2DV8]

Your alternator is not ok, It should be making 13 + volts at all times,
Autozone tests are worthless, Your alt needs to make 13 + volts and the amperage out put depends on how fast you spin it, Try new brushes first
Autozone sells them they install pretty easy in the back of the alt.
make sure you disconnect battery while you do this, or you will pop the under hood fuse.

 

[95strokerPSU]

Yeah I figured the autozone test was worthless.

I'm just thinking the fact that when revving the engine the voltage does not increase, should be a tell tale sign of someone thing specifically wrong.

What should the voltage on the stator wire be?

 

[FORCED2DV8]

The alt is interanally regulated, the voltage from the main wire ( the big Black one) should 13 + volts even at idle. The voltage varies from car to car but as long as its 13 or above or some where close its good, the voltage stays the same all thru your rpm range, you amperge however increase and decrease's at idle you might only make 50 amps, while at 3000 rpms your making 120 amps but still only 13 volts, Usually the brushes just wear out from use.. Unless the bearings are bad in your alt. just change the brushes. I think they are like 7 dollars.

 

[95strokerPSU]

Anyone have a write-up on how to change the brushes? Do I just need to take the volt reg. to get to them? And a friend was telling me I need to load the springs with something like a paperclip, is that true?

And does anyone know what the stator voltage should be?

 

[95strokerPSU]

Nevermind on the write-up, I found this....
http://fordfuelinjection.com/index.php?p=72

But would still like to know what the stator voltage shold be.

 

[95strokerPSU]

Just ordered a new voltage regulator with brushes in it from ffi for $25 and a new alt plug for $20. Hopefully this will solve my problem cause I hate throwing money at a problem and then finding it to be something else.

Anyone else think it's the brushes/volt reg?

 

[99FiveOh]

The alternator on our cars are pretty bullit proof. They only really need a new set of brushes and be good to go.

Your stator voltage is supposed to be around 8-10 volts. The new regulator/brush set should already have a pin holding the brushes back. All you do is install it, then pull out the pin. Should be good to go then.

 

[mo_dingo]

I thought we had a seperate voltage regulator mounted somewhere else in the car. Can someone please comment on that please???
Scott

 

[99FiveOh]

Nope, the only regulator is on the back of the alt. They refer to it as an "internal regulator", but it's really on the back of the alt instead of inside it.

 

[HISSIN50]

Scott, I think you're thinking of older foxes with an external regulator.