I have asked this question before with no response but I am trying again. Hopefully there is at least one person out there that can give me an answer.

I have a new battery. When I leave it hooked up to the car overnight it is dead the next day. Key is off. Nothing is on that I can tell.

What I did notice is that The voltage regulator is warm to the touch. This is without the engine running.

Bad voltage regulator or another problem.

heres how you find out where is the drain from your battery,, with the car off and the y key out , you get a digital mutimeter, you set it to Amp reading , disconnect the red battery terminal from the battery, connect 1 wire of the multimeter to the battery and the other to the red wire and read the Amps, if you do not have a radio it should read 0 if you have somewhere around 0.005 amps, if you have more than that you have a short-- (drain), to find where it is comming from just unplug the suspect item or circuit ( by removing the fuse of the board) every time you disconnect something look at the multimeter, you will find what is wrong when it goes back to 0, it is a PITA to do but that is the easiest way,

it work by measuring the power need by the car, to test that it is fine just turn on the radio,,, BTW DO NOT TRY TO START THE CAR or you will burn you multimeter,

try that and let me know

Thanks a lot, I will try tonight.

For me -

Mechanical Problem - Usually can find and fix.

Electrical Problem - Usually kind of lost.

Freezing14's advice is good in general but i suspect it won't help in your case...
it sounds to me like you have a bad (or very weak) diode in the alternator.

you might be able to see this with a scope on the charging circuit (i'd expect to see a lot of ripple) or there may be another charging system test that can confirm it.

there shouldn't be any current through the alternator with the key off. if there is, that could confirm it. worry - i don't have THE definitive test to prove this - but your symptoms match bad alternator ...

Sean,

Radio? The PO of my car installed a new radio and when I bought the car he told me to be sure and turn it off and remove the face plate otherwise the battery would drain. Fixing that is on my to-do list. just wondered if you have the same problem.

Matt