So my Dad's F150 battery goes dead if it is not started within a week or so. Battery has been replaced and the charging system checks out.

Finally got around to doing a parasitic load test today with my little ammeter. With the key off and no load at all (under hood light pulled) there is about a 0.27 amp draw on the battery (270 ma's). Too much.

So I pulled each fuse one by one, no change at all. I pulled all the wires from the alternator, no change at all. Constant .27 amp draw. Open a door, amp draw goes up to over 5 amps, so my meter is working.

Last thing I try is pulling the wires off the the solenoid (on the firewall, passenger side, just above battery). One wire goes to the alternator, and the other wire (large red wire) I think goes down to the starter? (not sure).There is a small third wire with a boot that did seem to have any amp draw either. Anyway, when I pull the second wire (not the alternator wire) amp draw goes to zero. These wires are held on by a 9/16 nut. Put it back on, .27 amp draw. So I figure this is my problem.

Question: 1.Does the second wire in fact go to the stater? (do not have a wiring diagram).

Question: 2. What on the starter could draw .27 amps all the time? Car starts fine, no issues other that slow battery drain.

Thanks in advance for any advice.

Charlie.

 

the small wire with the the boot is the "relay" from the ignition, to actuate the solenoid. The drivers side terminal should have no volts/amps as far as i know, possible corrosion inside the solenoid? not allowing it to fully disengage?

 

my 2003 f150 has battery drain if it sets for 1 or 2 days i think its something to do with circuit 15 what all does that control