Voltmeter shows Battery is good and Alternator is good. Battery still going dead. In Dec 2011 battery was going dead on random days. Then, for 5 months no problems, until last week when Truck wouldn't start. Had clicking. Had battery load tested.. came back good. Checked Alternator with Voltmeter, 14 V. I have an after market car alarm/autostart, could this be draining my battery randomly? Do I have a short somewhere? What else can I do to determine what the problem is?

 

Yup it can
but you need to find out what is killing bat
Start by unhooking alarm for a week or two then if you still have problems try radio window seats and on

 

I bought my truck used.. I do not know where the alarm is located, do I just pull the fuse?

 

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The aftermarket alarm could be the cause. You stated that the battery and alternator are good, how about the wiring? Any loose connections? Corrosion? Any other aftermarket equipment?

Louis
GM Customer Service

 

Noooooo lol

 

Under dash look for a box most are black
should be a cluster of wires take note of them most times its held on with zip ties see if u see a name on it or the remote may shed a clue then Google owner manual
some have a fuel shut off if tampered with but try unpluging cluster of wires on that box and see if truck start/runs don't kill battery
sometimes there will be a wire at battery terminal or fuse box that looks like it's extra


BEST TO TAKE IT TO SOMEONE IF YOU DONT KNOW AS IT CAN KILL YOUR TRUCK

 

I took my truck to Best buy and they showed me where it was, I disconnected the (Ultra) black box under the dash. After meeting with them, my battery died while sitting there, they charged the battery to 80%. This morning no issue, I will give it a couple of weeks and see what happens.
I called the Tech support for the brand or remote start/alarm system, the guy said the smaller module can sometimes go into sleep mode or something and cause the battery to drain. But who knows, hopefully this works and then I can figure out whats wrong with the box.

 

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