Engine run-on when ignition is off : Need Help !

[Mike_I]

Originally Posted by Blas

I note he has a one wire alternator which would render the dash mounted alternator light non-functioning (NOTE: All the external voltage regulator wiring should be removed or disconnected) so any bleed thru power from that light is eliminated from the electrical system. (This is in reference to the page 7 & 8 comment referred to earlier).
I know that radiator fans when turning from the air passing thru the radiator while driving can induce a small current into the system, but I would guess he is stopped when turning off the

My electric fan was the culprit when I had the same problem as the OP. Electric fan still runs when your stopped. When the ignition was turned off, the fan still took a minute to stop spinning and continued to induce voltage to the system until it spun down. Adding a relay took care of the problem. The alternator can induce the same scenario as the fan on spin down that's why msd includes the diode in the kit. Finally, as others have mentioned there are several possibilities that the OP needs to eliminate to solve his problem. Turning off the fan completely before shutting down the engine would eliminate that possibility. Removing the field wire on the alternator would eliminate that one. Should be pretty easy to try these two real quick. Good luck.