tire deflating problem

we have a 2000 hummer h1 the front tires deflated from 25 psi to 10 during the 20 to the 24 this is the second time this has happened the first time i caught them at 8 psi the battery was also dead what is wrong

I don't think the two issues are related. In cold weather it is not uncommon to get significantly more air leakage from the CTIS system. Leak in the CTIS system could be at one of the valves or lines. 1-2 PSI per week is normal for many trucks. My 1997 wagon was doing what your is doing now and I had a bad valve and some cracked CTIS lines. Not that it gets cold here in SoCal but when it was cooler it leaked far more than when it was warm. If you have a battery that is older than 3-4 years it probably just needs to be replaced. If it is newer then the obvious answer is you have a draw from somewhere. Most likely culprits are aftermarket add ons like DVD players, radios, etc. If you can provide a little more information the members can help you more easily.

check this:
http://www.hummerknowledgebase.com/tire/ctisleak.html
 
good diagnosis that has helped me

http://flashoffroad.com/electrical/Batteries/BatteryDrain.html
 
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