Hope someone can help me; I seem to have a power drain. Two weeks ago my truck, a 2002 1500 5.9 would not start so I get a jump started right up and then the next day it was dead again. I thought well maybe the battery was old and just not charging, so I went got a new battery and then the very next day it was dead again. I took the batter and alternator in and they both showed as being good. I have any aftermarket radio and a XM Radio that I have unplugged both them and all other accessories to eliminate them as problems and yet it still was dead the next day. The only way I can keep the battery alive is to disconnect it when I will not be driving it for at least 2 hours, once I plug it back in it starts up, so defiantly something draining it and I am unable to find the drain. I’m not sure if maybe the PCM is bad. I used a Multimeter to do some tests and a few are still getting power most notable to me are number 6 (ABS Pump) and number 8 (Wiper Motor) not sure if they should still be getting full power once the truck is fully off. Thanks any help.

Brian

 

I'd connect an AMP Meter or ammeter in line to see how much that something is drawing. Based on that information, I'm sure someone here can identify your power thief.

 

That's gotta be a really big power drain if it can kill a new battery within 2 hours. Um, without looking at the wiring specs I would think that the ABS pump would not need power with ignition off and I know that the wiper motor should be off. I'm not sure if the wipers even work with the key turned back to accessory power or if it needs to be turned forward to at least the on position. When they tested the battery, did they perform a load test on it? That will identify any possible dead cells. I wouldn't be able to say if a bad PCM could be the culprit, but the other thing that comes to mind is maybe a bad ignition switch - There's lot's of post about them going bad and causing weird issues like the blower motor not working at all. Off the top of my head I don't remember any specifically mentioning a battery draining situation but maybe if yours is going bad it may be keeping circuits closed when they should be open (or off). Since you said your wiper motor was still getting full power with key off, do your wipers turn on with the key off?