What is a "Junction Block Battery Feed circuit"/
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What is a "Junction Block Battery Feed circuit"/
My 1999 f-150 crew cab has developed a drain on battery of 7.5 volts with key out and ignition locked. Battery goes dead overnight. I systematically pulled all fuses and breakers one at a time from the power distribution box and when I got to #103 (a 50 amp fuse) the drain ceased. According to my owners manual, this is the Junction Box Battery Feed. Does anyone know what and where this circuit can be located??? As always, any help would be greatly appreciated. TJT
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From: Among javelinas and scorpions in Zoniestan
I don't have your model year wiring diagram, but I suspect it's the positive feed to your fuse block. With that fuse pulled, you've basically taken the battery off the electrical buss in the truck (except for the unfused connection to the starter motor).
Now, I suspect there was still something connected (fuse still installed in the fuse block) when you pulled this one? Or, is there some unfused wire going out of the block to an aux fuse point somewhere?
Maybe, you have a low level (high resistance) short in the fuse block itself. It would have to be something very minor, or it would probably heat up and start a fire or blow a fuse, depending where it is. I doubt this is the case though. I think there's something downstream of the fuse block that's causing the problem, and it's not protected IN the fuse block.
Any DIY additions to your truck? (Maybe ones done by a prior owner?)
- Jack
Now, I suspect there was still something connected (fuse still installed in the fuse block) when you pulled this one? Or, is there some unfused wire going out of the block to an aux fuse point somewhere?
Maybe, you have a low level (high resistance) short in the fuse block itself. It would have to be something very minor, or it would probably heat up and start a fire or blow a fuse, depending where it is. I doubt this is the case though. I think there's something downstream of the fuse block that's causing the problem, and it's not protected IN the fuse block.
Any DIY additions to your truck? (Maybe ones done by a prior owner?)
- Jack
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From: St. Louis (Out in the woods)
F103 supplies the under dash fuse box.
Go to it and continue your process of pulling one fuse at a time.
One caveat: You should bypass the driver's door latch so the GEM thinks the door is closed, then wait for the timeout - around 30-45 minutes - for the battery saver circuit to power down.
Go to it and continue your process of pulling one fuse at a time.
One caveat: You should bypass the driver's door latch so the GEM thinks the door is closed, then wait for the timeout - around 30-45 minutes - for the battery saver circuit to power down.
