odd volt light issue

[84TXGN]

I got home last night, turn the car (my dad's 85 t-type) and noticed the volt light was on. I turned the car back on and the light went off. i had a long day so i just left it over night. when i checked this morning the light was still on, turned the car on (didn't act like it had a low charge at all) and the light again went off. Anyone know what causes the volt light to be on with the key off?

 

[84TXGN]

UPDATE: now the battery is dead. Just tried it again and it won't even crank over.

 

[novaderrik]

i think that means the voltage regulator in the alternator is staying on all the time..
but i might be wrong..

 

[T-Type85David]

I had that same problem a few mths back or so. bad alternator Since i had LLT on it i just swapped it out for a new one but was planing on the 140 or so(sound system, hotwire etc all need juice ) Volt light would come on then go away, then stay on then go away. After the alternator i fig to clean up the grounds n i replaced the contacts in the back of the alternator with gold ones,WORKS GREAT MY alternator was about 20 or yrs old (rustly n dirty) nothing last forever

 

[Jerryl]

i think that means the voltage regulator in the alternator is staying on all the time..
but i might be wrong..

X2
Replace the alternator.
Sure, it may pass the test 3 times, but replace it.
Been there done that.