Alt?
 

So here's the story, I left for work and all was fine. stopped at the gas station, and when I started the car back up the central warning light came on along with the OXS light and the alt light. and the gauge was only reading at about 9 volts, it usually reads at about 13, so am I right to think the alt. went south? My car is an 82, any other suggestions ?

Use a multimeter to check the charging voltage while running.

check the 14 pin connector under the hood maybe its corroded and the alternator isnt charging
the exciter wire goes through the 14 pin

mine did the same thing as my alternator was dying... oxs sensor and stop lamp. It was a brand new battery, so i didnt consider it was the alt until it died out on me . but I would listen to those guys before your deal with pulling that thing off. SUCH A PAIN . that alt weighs like 30 pounds and if you dont have a lift or jack stands you will want to cry ...

just changed had my alt checked and had a similar problem gauge was reading 9v but when i checked it with a charging meter it read 13 1/2 volts. i found out theres a resistor in the back of the cluster that works the gauge. thats whats wrong. i have a 79 5sp im not sure if there the same set up

Ugh. Shoulda checked voltage at the front post first before buying another Alt. You gotta spare now.