My truck is running great. The problem is a phantom drain which kills the battery overnight. Does anyone have a troubleshooting recipe for finding where the drain is? When the key is off, where should I check with my meter to find power where there should be none?

 

Every night pull a different fuse, this will narrow down which circuit is draining it.

If you want a faster method, hook your meter up in series and measure the current draw. Pull fuses one at a time until the drain disappears or lessens. That is the circuit you need to look at.

 

Sorry to be slow but when you say in series do you mean that I should run the power through my meter from the main power wire?

 

Yes, only do that with the truck not running and have your meter set to measure current and up to 10amps if you have that setting. You can adjust to a smaller current setting after seeing how much is actually flowing, prevents from wrecking or at the very least blowing the fuse in your meter.

 

http://www.youtube.com/watch?v=dt5Z2NfcBac

 

Thanks Biltit appreciate your help! Youtube is amazing, I always go here first for diesel info but youtube has answered everything else I've come across.

 

An added procedure.

Set your multimeter to read the draw. If the draw is high enough to kill your battery, have someone start pulling fuses individually until the amp draw drops to what would be considered normal, such as the draw of your clock. Make sure there are no interior lights or under hood lights activated at that time.

When they pull the correct circuit fuse, you'll have a starting point of where to look.


WHen we were kids just beginning to play around with cars, multimeters weren't available for us to use. We would simply disconnect the negative post cable, and place a test light between the cable and post, and perform the same procedure. A light glow was normal for a clock, but if it was sparkling bright, there was a dead short to find.


Technology has made this so much more accurate.



T.

 

Ever think of a bad battery that won't hold it's charge.

 

I would think of that possibility but it's a new 31, lots of amps. Also lets me know it has to be a major draw to go down over night.

 

Thanks for the help, the problem was that the wires my new gauges were reversed. Just interchanged the fuse taps and all was good.