alternator problem

My alternator isn't charging on my 1988 mighty max 2.0. I took the alternator to advance auto and they put it on the machine and said that it was good. The guy said something about a fuse that is somewhere between the alternator and the ignition. Does anyone know what fuse this is? I read that if it is blown it can cause the alternator to not charge? Thanks

it may not be a normal fuse. they also have fusable links that go in between the altanator an the 1st thing the wire conects to. you can change that wire an put a normal fuse in it like 1 for a sound system but with a big fuse or find a breaker or something.lol check if u have voltage on the altanator its self then test where the wire from the altanator to where it ends an see if u have voltage. if u dont then theres your problem

These alternators have a built in regualtor. Controls how much amperage they put to the battery, and to do that they sample the battery as the engine is running.

You have a total of 3 wires to the alternator. Big one is the output to the battery.

The other two go to the built in regulator. One should show 12 volts with the key on. That twelve volts excites the field in the alternator and causes the alternator to "generate" electricity.

The other one monitors the condition of the battery and tells the regulator how much current to put to the field. Not sure which one is which.

The parts store says your alt. is good? That means that your alternator isn't getting 12 volts input to the field windings.

Or, it could be that the big wire, which ends up back at the battery, is not getting power to the battery.

A quick "shade tree mechanic" method to see whether your alternator is making power is to start the engine, then suspend a long bladed screwdriver or a hacksaw blade just a little bit away from either the center portion of the back of the alternator- where the shaft would come out the back of the housing if it could- right where it revolves in its' bearing, or on the front of the alt. at the center where you tighten the nut on the shaft.

If the field windings are getting power from the regulator, the screwdriver/hacksaw blade will be drawn to the alternator shaft by the magnetism created by it operating.

Just get it close and it should draw it right against the end of the shaft or bearing housing.

That should give you an idea of what you have going on. I don't know if they even have a fuse in the alternator system at all.....