Charging System

[jimmyjamed]

The alternator is (should be) trying to keep the voltage at ~13.5, and it should be doing this almost instantly after startup, maybe a second or two.

Depending on what voltage the batt is and the loads(lights, stereo etc) will determine how much current is going to be flowing.

The alternator doesn't let the batt go down to 11 volts before it starts charging. It puts out a constant voltage, varying very slightly, unless its loaded down hard or not spinning fast enough. Your battery would be fried in short order if it were run down, charged up, run down, charged up all the time.

It sounds to me the the alt is bad. It may be able to put out 14 volts, but when it gets loaded down it can't hang and the voltage drops. I don't know if the tester the store is using loads the alternator or just spins it up and measures the voltage.

Put in the 130 amp. I did and it made a big difference. Now the voltage doesn't drop at idle with the underdrive pullies!

Also, unless you have a clamp-on ammeter for that fluke, don't try to measure the current. Your meter will only measure 10 amps max, more than likely, and your alternator (if it was good) has the capability to put out ~60 amps. I don't think the 10 amp scale on your meter is fused, so something is gonna burn if theres much more than 10 amps flowing.