Electrical system went dead

[utah300rum]

I went to open my truck the other day and my power locks wouldnt work. I opened up the truck and the element in the interior lights barely turned orange. The batteries were DEAD! I put 2 brand new batteries in it 8/06 and only have put on about 4-5k miles on the truck since then.

I have a nice new battery charger so I hooked it to the battery on the passenger side and it would not even try to charge gave me a code: open cell/sulfate problem. I tried twice, same code. So I hooked it to the battery on the driver side and it started to charge. The are in parralel so I dont know why that made a difference. It ramped all the way up to 29 amps on the charge meter. WOW I have never seen that even when I accidently left a light on in my camp trailer for over two weeks, it only went up to 18-19 amps and recharged in 6-8 hours. It took over 24 hours to recharge the batteries on the truck.

I put an amp meter on my cables and cant find an obvious draw anywhere. I left the truck alone for 24 hours then re-tested the batteries and they were still full.

Anybody have any ideas?

I really dont want to get stuck somewhere with dead batteries.

[alabamafrog]

On my truck the vacuum pump will kick on every now and then with the truck parked and off. Just a wild guess but maybe if it has a small leak and sits a lot then the pump might be draining it. I drive mine almost everyday so I haven't experienced any problems like that.

[utah300rum]

My truck sits alot, so I try to start it every few weeks or so and idle for 15 minutes. Or take it to the store and back. What is wierd is I actually have been driving my truck lately. I have put more miles on it from christmas til now than all of 2007 put together. I took it on a trip to the inlaws 4 hours away each way, then took it up to a resort couple hours away. Then I left the car seats in it, so my wife was driving it 3-4 days a week. Then I parked it a couple of weeks ago and that was the first time I tried to start it. I have let it sit for a lot longer than 2 weeks before.

I guess I will let it sit for a week or so then retest the batteries. I am really hoping it was a fluke like a light relay stuck on or something stupid. I think I would have noticed a light left on.