HELP!! Parasitic Battery Draw
 

Hi Everybody!

Recently picked up my first Cummins... It's a '92 Clubcab 4x4 and I'm stoked! Only problem is the PO neglected to mention that the battery will die overnight. I'm in the process of trying to detect which circuit is causing the draw but I'm having issues. I'm fairly mechanically inclined and resourceful but with limited knowledge/experience with electrical systems. Forgive me if this has been answered somewhere else... I haven't been able to find it. Any help is appreciated!

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So I got the battery charged/checked at autozone and they said it was "good". I disconnected the negative battery cable from the post, measured across the cable to the post with my multimeter, and it reads about 12.5v... I also measured across from the core support to the negative terminal and I get the same reading. Negative to positive terminals of the battery also measure about 12.5v.

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So am I doing something wrong or is it like it appears and I might as well just hook up the positive battery cable to the frame? I checked all the doors and lights/accessories I could to make sure everything was off. Should I just start pulling fuses or is it something more severe than that considering the reading is practically the same as the batteries charge?

Thanks again for any help!

From full voltage to dead is a large drop, try to unhook your alternator and let it set overnight. it is more than likely not loosing a full charge through a 16 gauge wire. if the alternator being unhooked causes it to keep a charge, start doing wire continuity tests and possibly replace the alternator. these draws are very tough to chase through a computer the best we can do is give you a few things to try. you are responsible for testing everything properly and giving us the right information :c:

Its a long process but your on the right track I prefer a test light cause you can watch it take out the fuses one by one to and the alternator ex... good luck

Test lights work, I prefer a powerprobe but once again, good luck!