I just put a 94 amp alternator in my 79 monte carlo and it used to have a 64 amp, and now my battery light is staying on constantly. Its draining my battery, if i disconnect the wire the light turns off but my alarm doesnt work. Any advice?

 

I changed my alternator now my battery light wont turn off.

 

I can think of 2 things that may be happening:

1) you replaced a Delco Remy alternator with a Bosch or vise versa (the wiring is different)

2) You installed an aftermarket '1 wire' alternator in which case plugging the exciter/light plug is not required.

More info about the old/new would be helpful.