Hey carcrazy... bad *** Charger. Anyway, if you have clearance, you can take a regular old non-magnetic flat screwdriver & put it behind the "center axis" of the alternator on the back side (a raised metal flat circle about the size of a nickel, dead center in back). If the alternator is charging, that nickel sized center spot will be magnetic, if it's not, then you're not charging. Also, you can put a simple voltmeter on the pos/neg of the battery itself. If it's not charging, you'll be about 12 volts. If it is charging, you'll be about 14.5 volts.
Other things to check... I "think" you've got 3 wires on the back of your alternator. One really big one with a nut holding it in place & 2 smaller ones that have slip-on spade connector ends. The really big one with the nut is the main power wire. It goes through the bulkhead disconnect (3 pig multi-wire plugs on firewall near brake master cylinder), then through the amp meter, then ignition switch (I think), but for sure end up at the positive post on the battery. You should be able to measure 12 volts at the big alternator wire terminal (while wire is connected) with an electric meter. If you have an issue with your dash amp meter, you can run a really big wire (maybe 6 gage?) from the nut connector on the back of the alternator directly to the positive side of the battery & it will charge.
The other two wires are called "field wires" and basically they tell the alternator when to charge & when not to charge. When they're at 12 volts, the alternator charges. When one or both don't have voltage, the alternator doesn't charge. I can't remember exactly where those wires come from...maybe out of the ignition wiring or ballast resistor?... but a wiring diagram should help you track those down. Regardless, I'm pretty sure both of the small field wires should be 12 volts for the system to charge & you can test this with the engine running & sticking an electric meter probe onto the back of those wires while hooked up to the alternator. WATCH YOUR HANDS OR USE EXTENSION WIRES since the engine will be running.
