2003 f250 7.3l diesel
something is killing the battery in a matter of minutes from a full charge.
Chain of events:
2 new batteries, worked for a couple weeks, got in the truck, dead.
Recharged batteries, cranked truck, all worked. Turned off truck, everything off, no delays as there usually are, ie window, radio running till door open, everything off...pull out key...everything comes back on in about 15 secs...
checked all relays, checked all fuses...fuse 35 will turn everything off and so will the pcm relay. Unlike all other problems I have read, ours does not shut off and stay off, it shuts off, then click, ding, all back on. Truck does not start the motor itself.....yet....(thats when we drive it into the pond). We changed the ignition switch, dont see any water in the pcm, would the gem cause this? We changed out the instrument cluster, thought maybe it was the battery saver relay, but everything was the same. Weirdest part is the speed in which the batteries drain, within minutes....any ideas??PLEASE!

 

Well, to drain the batteries in minutes, it's going to be a BIG load. Check the obvious first. (Since it takes a big cable to transfer a big load) Starter cables going from the battery(ies) to the starter, block, and up to the alternator. If you have a hot cable worn through and welding itself to a ground, when you pull the key, it's merely completing the circuit elsewhere.