Battery drain on 2002 GM Silverado Truck: No Codes

Question:

My battery loses charged if I leave the truck parked for over 3 days. I believe this battery is still the original one from the dealer but I am not sure because I am the 2nd owner. However, every time I boosted it, it seems OK for the rest of the day. How do I check it?

ATS Advisor:


Battery can be checked visually by reading the info on the paper glued to it and you can compare the date the battery was made against the vehicle date of manufacture. This will tell you if it comes with the truck. You can also test it by putting a voltmeter between the vehicle metal grounds against battery negative cable (remove it). With all doors shut and accessories off, the maximum reading should not exceed 0.250 volt. Higher than this means you have a drain from one of your wiring or engine computer modules. Finally, if the battery has a sight glass, make sure it is a solid green color which indicates that the battery is fully charged.

ATS Tips:

IF you have a drain, get a wiring diagram from ATS to trace the short or unplug your fuse one at a time until the drain goes away.

If you have no drain (lower than 0.250 volt), replace the battery.

You have to wait at least 45 minutes when measuring the drain. Some of this vehicle has a timer inside to automatically remove the load. Contact ATS for more detailed info.