What is wrong with my 93 Ford Explorer?

[RazRbladeKisses]

A week ago went to start it up and it wouldn't start. The battery was completely dead. Charged the battery overnight and went over to Battery Wharehouse. They checked the battery and said it was still holding a charge, but there's 8 AMPS draining somewhere else...causing the battery to go dead. They recommended to disconnect the negative cable when SUV in not in use, so the battery doesn't go dead again.

We've been doing this and battery has lasted. I've talked on the phone with my mechanic and described problem and he thinks it could be ABS or the radio.

Any help would be greatful!!!!!!
The radio and A/C also don't work. When we bought the SUV, they both worked.
Yes the radio is on top of A/C and heating controls
Already did a fuse test. Checked the alternator. They are also good.

 

[DS113]

easiest way to find it is put a metre across the battery so it shows the voltage loss and then pull the fuses out one by one! When you find the circuit that's causing the problem the voltage drop will disappear that will be where the problem is. You can leave that fuse out and you will have no more problems of a flat battery BUT you wont be able to use anything on that circuit as unless you put the fuse back in NOTHING (on that circuit) will work