Like many, I have been fighting the battery drain issue for a little over a year. Batteries are fine for a month, then 24 hours later, dead. It has become more frequent over the last 2 months now. My question is if you were to put a toggle kill switch on the system to cut all power from leaving the batteries while it is sitting in the driveway, how would you do that? Also, would that effect the grid heaters from functioning when the truck is plugged in? I'm sure it is the fuse 51 issue as many have discussed, but it only is dead when you need it most of course. Luckily, it has been in the driveway every time that it has died. Any help will be greatly appriciated.

 

If you put a kill switch, it will not affect the block heater. It is a simple circuit that doesn't interact in any direct way with the electronics in the truck. The electronics will detect the warmed block. The grid heaters are strictly battery powered and only cycle with the key on.

 

Installing a battery cut off is not that difficult. You can buy the switches and components at Summit Racing.

But, if you're draining batteries, you have a short somewhere. You really need to find and fix that before it gets worse - possibly causing a fire.

 

I would bet money that your a/c fan comes on after you turn the key off and remove it. I figured out mine was doing this. Next time you turn the key off, wiggle it around a little bit in the off position and see if your fan comes on. I changed the ignition switch and it fixed the problem for about 2 months, so I'm not sure what the actual root cause of the problem is. Some guys have bypassed the ignition switch with the fan circuit by installing a relay. I might have to do that.

 

I tried the key and fan thing. Not that. I assume it is fuse 51 like everyone else's, but have not hand a chance to verify that. The short and fire makes me nervious though!!!!!

 

A battery disconnect on each battery might be a good temporary measure until you get the problem fixed . The ones I'm most familiar with are a specialized terminal with a **** attached to break the circuit. The big downside of that is that you would need to butcher your trucks battery cables to install them. I think they have a stud that would require a cable with an eyelet terminal on the end. Seems like a pretty big deal-breaker, at least to me.

Another remote possibility would be to get a small battery tender, mount it under the hood permanently and wire it into your batteries. Then you can keep it plugged in when you are parked (provided that you are able) and keep the batteries topped up. Again, this would only be a temporary measure until you find the trouble.

 

You can't wire a cut off switch in because the draw is likely directly off the PDC. The ECU draws a trickle all the time and if something goes wrong that can accelerate.

A battery disconnect would the only solution but it may loose some programming after sitting for too long.

Best solution is find the draw. I assume you have replaced the batteries with new ones?

 

WL.

I had a battery on a old tractor that pull that crap.

final i took the battery to a guy that knew his business about batteries.

he charged the battery up to full charge,

removed the battery caps,

then he placed a major load on the battery, like when you are starting the vehicle.

Note: we both were wearing eye protection

as the battery was on full load, he looked down into each cell.

then told me to look down in cell 3, there was a line of very small bubbles coming up to the top of the fluid level in that cell.

he said that cell was bad and what was running the battery down, would take a while for the battery to go down, but it would in a few days.

new battery fixed the problem: