ok so i have a 92' 3.0 and about 2 months ago it started draining my battery completly dead overnight!! it is a completely stock truck even the radio and such NO aftermarket parts. i have put a brand new battery and Alternator as welli have replaced the ground wires under tge hood all 3 of them....SUGGESTIONS ANYONE PLEASE!!!!
I'm playing with the exact same thing on my '86 right now. I'm assuming that you've verified a good battery by disconnecting the battery overnight and seeing if holds a charge?
Here's what I've done. Get a voltmeter, set it to 10amp. Turn everything off. Doublecheck this, turn EVERYTHING off, close all your doors, remove the bulb if there's an underhood light, etc. Now disconnect your positive battery cable, and set up your voltmeter inline, negative lead to positive battery terminal and positive lead to positive battery cable. A reading of 0 is ideal, of course, but won't happen. Under .03 is good. If you're draining overnight, you'll likely be reading over .20 amps. Mine reads .23, and just barely holds a charge overnight.
Now start pulling fuses, one at a time. If you're lucky, it's just one circuit doing it, and your amp reading will drop to respectable levels when that fuse is pulled, and this will give you a ballpark when you start chasing wires through your harness.
If you're reading under .05 amp draw, then I'm confused. If there's no change after pulling the fuses, suspect the supply wire to the fuse box (you won't be that lucky
).
