Hello everyone,

Locally we had the coldest night temps of the year so far. On the coldest night I came out to my truck to start it and the battery was dead After i had it jumped it drove fine. Since then I have had to jump the truck every morning after the truck has sat overnight. Had the battery and alternator tested both are fine. I am thinking that i have a short somewhere but have no idea how to test and isolate any electrical draw off the battery. I have nothing on inside the truck no phone charger etc and have nothing aftermarket hooked to the battery. Any ideas?

 

Its an 03 with the 5.3L and 4 whell drive if that helps

 

First, you have to determine how many amps your system in drawing. There are two simple ways to check this.

1) Use a standard volt meter. They have a way to use the meter as an ammeter. Just be careful. Many of these meters usually have a max rating of 10amps (internal replaceable fuse usually). Read your meter's owners manual to determine exactly how to use it. With the truck off, pull the positive cable off the battery. Put the meter inline between the positive terminal and battery.

2) Or you can buy a meter like the one I have. http://www.sears.com/shc/s/p_10153_12605_03482369000P

These are great. You can just clamp it around the cable and tell the amps without any worries. It is great for measuring amps for both the alternator and starter. Great all around meter.

You should not pull more than a few (2amps or so). If you are, you can have a friend start pulling fuses to determine what circuit has the excessive draw.

Hope that helps getting you started.

Eric

Ps, Don't be surprised if you determine that there is no excessive draw on your system. When it gets cold, batteries take a poop. They will sometimes still test good, but they are bad.

 

thanks Eric. I will give that a try tommorrow. I had the starter, battery and alternator checked at Oreilys today and everything was good. We hooked my truck up to a snapon fleet voltmeter and charger. We were reading at a 12.48 volts and were checking for a draw on the battery. the truck failed to start again when it read at 12.45 volts so i figured i might have a loose connection (we had been fiddling with my dash lights). I removed tested and re-installed my starter and retightened all my connections on my battery and the truck started right up. I am hoping this means a loose connection was fixed. Ill check in the morning and let you know.

 

2 amps is way too much needs to be under .050amps or 50mA

 

Thanks MD, I didn't look up the exact specs. Figured someone would throw it out there.

Dopeoperator, sounds like you figured it out. I'm glad it was just a loose connections.

Eric

 

I am thinking it was a loose connection. The truck has started up fine every time today. Thanks for all the advice. If it happens again ill let you know and try the amp meter technique.