Chevrolet Repair: 1994 Chevrolet k1500 alternator issues, jumper cable, chevrolet k1500

Question
I recently have gotten a low battery light on my dash in my truck and the gauge is reading around 12v on my dash.  I checked the battery with a multimeter and the battery reads 12.22v, then checked the alternator from the positive on the back to the body for a reading and the multimeter displays 0.80v.  I replaced the fuseable link to the battery and my belt.  What could be the problem that my alternator is not putting out any power?

Answer
HART, CK THE BACK SIDE OF THE ALTERNATOR POST AGAIN,MAKE SURE YOU HAVE A GOOD CONNECTION WITH YOUR METER.. YOU SHOULD HAVE BATTERY VOLTAGE HERE.[12 VOLTS.] IF NOT, CK THAT CABLE FROM THAT POINT TO THE BATTERY OR SEE IF THERE IS ANOTHER FUSEABLE LINK IN THAT CABLE. SOME DO AND SOME DONT.  THERE MAYBE A OPEN IN THIS CABLE. VERY RARE HOWEVER. DID YOU RECENTLY JUMP THIS ? IF SO THIS COULD CAUSE A IN LINE FUSE TO POP. IF NO POWER THERE GET A JUMPER CABLE AND HOOK TO POS SIDE OF BATTERY AND THE BACK OF THE ALTERNATOR. SEE IF IT CHARGES LIKE THIS, IF SO THE CABLE HAS A OPEN IN IT FOR SURE.. IF THERE ARE 12 VOLTS TO THIS CABLE, REMOVE THE PLUG ON TOP SIDE OF ALT,TURN THE KEY ON AND WITH A TEST LIGHT CK FOR POWER ON THESE WIRES OR WIRE. WHILE TEST LITE IS IN THE TERMINAL SEE IF THE BATT LIGHT LIGHTS UP ON THE DASH,IF SO THE ALT IS BAD. NO OUTPUT..TIME FOR A NEW ALT..LET ME KNOW IF YOU NEED MORE INFO..TOM..