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I have a 99 7.3 and I’m having a small battery draw. I just had the alternator and both year old batteries (Group 65, 750 CCA Champion:cheapies) tested today and everything was good. I think it’s a draw because I cleaned the terminals and when I put the last negative terminal on it baby arced. Reason for having them tested was if I don’t drive it for a day or two it won’t have enough *** to start. I disconnected both negative cables before I go to bed and am going to hook em back up in the morning to see it it cranks any better. Thanks in advance, Jake
 

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So, of course it sparks, it's supposed to...

You need actual readings, with a meter, to know if that draw is too much.

So you're assuming your batteries Are good and that the Charging System is doing it's job keeping them charged. Verify That! If that's OK, you have a sub system with, what's called, a Parasitic Draw that you need to find. This used to be simple, it no longer is with modern electronics because not only is there Always a "draw", that draw is Much higher initially and then subsides after about 20mins if undisturbed (no door opening or or Anything that "wakes-up" modules and starts it all over again).

The most common areas for us are - the Radio, Alt, Dash Cluster. Start with the Alt. Remove all wires from it (be careful not to let them touch Ground). See if that stops it. If not, next pull fuses from the other two and look for an improvement.

If all that checks-out it's time to Roll Up Your Sleeves and prepare for a Fight :( The simple, and time consuming, approach is to pull 1/2 the fuses. If it stops put 1/2 of those back and see which 1/2 has the problem until you narrow down the circuit. If it doesn't, put the original ones back in and pull the Other 1/2 and repeat.

OR get out a Meter and go to work ->

Your truck is different than the car in that video though. First you have to disconnect one of your batteries (pull the Neg cable) and test the draw through the remaining one Only. Next the 50Ma draw is much lower that you'll ever see from your truck (mine draws, eventually after everything shuts-down, over 150Ma - something our dual batteries tolerate well).
 
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