1995 Chevy S-10

You have to start with getting a Digital Multimeter. Not a test light. Remove the Negative battery cable. Set the meter to "amps". Connect one lead to the neg. Battery post and the other lead to the neg. Cable. Observe the reading. There will be SOME amperage all the time. This will be for the clock memory, etc. When you connect the meter, you will see a good bit of amperage at first but give it about 30 seconds to a minute for the computer to 'go to sleep'. After a minute, observe the reading. It should be less than 0.050 amps or so. That's not an exact spec so give or take a little on that reading. As long as there is a '0' immediately after the decimal, you're usually ok. If the reading is, say, 0.167 amps. That's TOO much and will run the battery down in a day or two or three. This is when you need to start pulling fuses, one at a time, watching the meter after pulling each fuse. If the draw does NOT go away, put the fuse back in and move to the next one. When the draw DOES go away, make a note of which fuse you pulled and get back with me. A note to add from my experience is that when you find the fuse that removes the draw, don't stop til you've pulled each fuse, one at a time. One fuse may feed another fuse. If you pull the 'feed' fuse and the draw goes away, that fuse MAY feed too much to chase. Put that fuse back in, making a note as to which one it is, and keep going. The reason is, another fuse, that that fuse feeds may take away the draw and be WAY more narrowed down as far as the circuits that are protected. Make a note of ALL the fuses that reduced the draw and get back with me and we'll trace it down.