We have an audible battery draw on our 1985 F150. Each time the truck is turned off the battery cable has to be taken off. If we forget the truck is dead within an hour or two. The battery is brand new, so it has to be something else. It has a relatively new radio but it's not anything fancy. Other than that it's all stock. Any suggestions on what to check?

 

Get a testlight and hook it up like the picture above. Then start pulling fuses to see if you can get the light to go out. You will need to shut the door each time, the domelight will be a drain and make the light come on.

If you can't find any fuse that makes the light go out, then take the wires off the alternator and then see if the light goes out. When the light goes out or glows very very dimly, then that's your drain.

 

These come in handy if it's something you find yourself looking for drains very often.
20 Amp Automotive Fuse Circuit Tester
They have, or used to have, a 30A version also.

For most people a test light, or meter, is fine.

 

Looks like a very handy tool and cheap too. If I could remember my HF password I'd put it on my wishlist.

 

Ran across something similar on my 86 F250 351W The wiring harness behind the alternator got chaffed and was shorted to ground, killing the battery.