I have a 98 Ram 1500 with a 5.2. If i leave the battery hooked up overnight my truck will be dead in the morning. I took a multimeter and tested the voltage between the ground wire to the battery and the negative post on the battery and it reads around 12v, which indicated a Positive wire is touching the body. Ive removed every fuse (under the hood and in the cab) one by one and never saw a change in the voltage, ive checked the wires to the starter and alternator and still nothing. any ideas of what could be causing this?

 

do you have any additional lights, radio,CB, etc? double check your wireing.

 

Huh? I'm at a loss for how to parse that in a way that makes sense. If a B+ wire were against the chassis then connecting the battery cables to the battery should make smoke somewhere.

Get your hands on a clamp-on DC ammeter. Zero it out, clamp it around either all of the positive cables or all of the negative cables at the battery. If there's more than about 0.125A flowing with everything switched off (all lights off, key off, etc.) pull fuses one at a time, reinserting each before moving on to the next, to determine which circuit's presenting a load to the battery. If you've got accessories kludged into the system, don't forget to include their fuses in your isolation steps. Once you find the offending circuit, go from there.

 

Check the glove box lite. Make sure it's not stuck on.

 

"If a B+ wire were against the chassis then connecting the battery cables to the battery should make smoke somewhere."


Thats what i thought too, and ive had a few people check it out also. the truck starts up and runs fine, no fuses blow, and nothing sparks or anything like that. its had this problem for months and I've just been unhooking the battery at night. i dont know how whatever is causing this hasn't blown some fuses or burnt some wires.

 

i installed an aftermarket stereo but have triple checked everything around that

 

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It's not a B+ wire against the chassis then, eh? That would make smoke, guarandamteed.

Something's drawing current that it shouldn't. If it's not the glove box light (as has been suggested, and wisely because it's a common failure) then you're just going to have to troubleshoot the problem. Without a clamp-on ammeter it's going to be damnably difficult to do. I've seen more than one vehicle with battery disconnect switches or a master disconnect solenoid wired in because the problem proved too elusive, but have yet to see one I couldn't fix in one afternoon using a clamp-on ammeter and the appropriate documentation. (I troubleshoot a bit faster than most -- used to make my living as a field engineer.)

And, hey, it's an excuse to buy tools. cragslist, pawn shops, etc. are good places to look for used test equipment -- you should be able to find something suitable in a DC ammeter for well less than a Benjamin. Heck, you can buy something new and suitable though not great for about a Benjie, for that matter.