This is a 1990 F150 standard cab 1/2ton 4WD manual trans. 5 liter engine. Fuel Injection.

It's 5 below zero outside. This truck actually started this morning when it was 21 below (that was great). The truck is still suffering from the idle gone whacko problem (described in the "engines" forum on here). Otherwise it runs fine. However, tonight another ghost got into the truck.

I parked the truck and fortunately I left something in it. A half hour later I go to the truck, it's shut off, key removed, and the fuel pump is still running in the tank. I heard the hum, and could not understand what was going on. I traced the sound to the front tank (the only one that works). The ign switch is OFF. I started the truck, made sure the switch was in the OFF position, removed the key, and the pump just kept running. I thought about turning the switch to the rear tank (dead pump), but maybe something else would drain the battery, and at 5 below zero, I am not about to f**k with it.

What the heck??????

I just pulled one of the battery cables for now. What could cause this? I know it's electrical, but shouldn't the IGN switch shut everything off?

One thought, could it be so cold that the switch is not actually shutting to the off position? (It never did this before). I wonder if some lock spray would help, or PB blaster in the IGN keyhole????

Any ideas?

*Does anyone happen to have a wiring diagram they could post or email me.

Thanks

George