Low Charging - Alternator Problems?

[fastsvo]

Hi Guys,

I have a 165amp 3G alternator (large case) on my '91 that was purchased from a reputable seller on ebay aka "zbeav@aol.com" a few years ago and not many miles have been driven on the car (it's been in storage mostly).

Ok, this alternator has always done an excellent job of charging the system and the other night I noticed the alternator gauge was staying down below the 1/4 mark and would not budge as the rpm's rose.

Put the charger on the battery and was surprised to find that it did required some charging time (car ran pretty good before hand).

So here are tests that I have performed so far:

Engine not running & ignition on

1) Disconnected the D connector with the 3 wires and measured the voltage on the lt green/red wire = 12 volts CHECK

2) Reconnected the D plug to the alternator and probed the greed/red wire. I should be seeing 2.4 - 2.6 volts here but I got 3.8 volts ..... a problem? I understand if I had no voltage at all here, then I would have had a failed regulator.

Engine Running & ignition on.

1) Probed the green/red wire and I should be seeing battery voltage minus .25 to 1.0 volt. My battery at this time was @ 12.92 volts (discharging?) and probing this area got me 12.15 volts.

2) Probed red lead to the charge stud on back of the alternator. The battery at this time was showing 12.5 volts. The Charge stud varied on my DVM between 18.10 - 19.15 and sometimes just 1_.__ (did it exceed the value? DVM set at 20volts DC).

Is my alternator perhaps overcharging the system here? Does the 3.8 volts received from the D plug point to a bad voltage regulator? Bad alternator?

I have yet to pull the 200 amp blade fuse and measure the resistance.

Any help would be appreciated here.

Thanks in advance,

Eric

[goodyear1984]

well i didnt read everyting u said but one thing that people dont do is rewire the alternator to the solinoid i did this on my stock alt with thicker wire and it charged way better