Parasitic draw 93 f250 7.5l

ford
batteries
f250

#1

Would anyone happen to have a spec on acceptable parasitic draw with the key off on this vehicle? 1993 F250 7.5. Pulled all fuses and it didn’t change the nearly 1 amp that is being drawn with the vehicle off.



Been having a dead battery if the truck sits for a few days.



Thanks!


#2

Normal draw for most vehicles should be less than 30 milliamps, one amp is way out of line, as you know. Try disconnecting the wiring to the alternator to see if that kills the high current draw.

Here is a link that may help you out.
http://www.aa1car.com/library/battery_runs_down.htm


#3

thanks for the reply - it’s not quite 1 amp and I have no known amp drawing device to calibrate the meter, but that’s the best I’ve got!

I did disconnect the alternator, regulator plug caused no change but the output connector did cause a slight drop. Still a significant draw (more than half an amp) though…need to check better to see if it has any engine compartment fuses or relays that I can try pulling next I guess.


#4

Some late model Fords have a pretty substantial current draw before things settle down and they go to sleep. Both of my Lincolns and my son’s Lincoln pull about 700 milliamps, give or take, for about an hour before they settle down to a 100ish or so.

If all fuses, and fusible links, are pulled and the problem still exists after the alternator has been unplugged then about all I could suggest is to disconnect the ECM and any security system module to see if the draw goes away.
Without having a schematic in hand I’m not sure where all the power wanders off to.


#5

thanks - I’ll re-run the test with at least an hour wait with the meter hooked up. I also need to, as I said, double check that I got any and all underhood fuses, breakers, etc.