Hello,

I have a parasitic draw on my truck that is killing my battery. I leave my truck parked for about a week while I use a company vehicle, only to find the battery is stone dead when I try to start it. I have disconnected the battery and measured the current draw while the truck is off and come up with 0.140 amps. Door is closed and dome lamps are off while testing.

I left the meter connected and started pulling fuses and discovered that if I remove the 5 A fuse on circuit #15 inside the cab fuse panel, that the draw drops down to 0.005 amps. Upon removing the fuse I noticed the battery saver relay (#4) had clicked, so I removed the relay and left the fuse installed and noticed the draw was still 0.070 amps. I know the relay is supposed to click off after about 45 minutes, but even with the relay removed the 0.070 amps seems a bit excessive to me.

I did a lot of searching on the internet but have not come up with a cause or a solution, there was something mentioned about a speed control recall (which I believe is an inline fuse installed on a pressure switch off the master cylinder which I appear to have done already). Does anybody have a diagram of circuit 15 so that I can start unplugging modules to try and isolate the source of my current draw?

TIA!

Edit 5.2L V8 XLT

 

You have to wait 40 minutes after doing ANYTHING for the battery saver to time out, otherwise you'll end up chasing a mystery 150 mA current draw.

Normal idle current after the timeout is usually 40-75 mA, an amount a good battery should be able to provide for many weeks.

Pull the connector off the speed control switch on the master cylinder and inspect it for brake fluid and also whether the recall was done. If the connector is wet with brake fluid or the recall hasn't been done, do not reconnect the connector unless you want to risk having the truck go up in flames.