Take a test light and remove the pos. battery cable, hook up the wire on the test light to the Neg battery post and hold the test light between the pos post of the battery and the loose battery terminal. If the test light lights up you have a draw. Have a freind start pulling fuses one by one until the light goes out, if a fuse makes the light go out then you've found the circut that has the short and you can trace it from there. If all the fuses are pulled and the light is still lit, then your short is (on a GM) between the battery and the starter Sol. or the wires from the sol to the egn. switch, you can cont. with the same proc. by removing the wires one by one from the sol.