1991 Isuzu Trooper 2.8 TD

There's a fairly common problem in these vehicles with the heater blower
not working and the warning lights coming on. It's caused by the
alternator not energizing the blue charge relay or the relay itself.
I seem to be having the opposite problem.

This morning after a short drive the blower wouldn't shut off after I
stopped the engine. There is no power to any of the other accessories,
etc. I turned it to "ON" again and only the oil pressure light comes on.
It is not a problem with the blue relay itself because I replaced it
and it didn't help. When I pull the blue one, though, the blower does stop.

Any help would be greatly appreciated. Do you think there is a relay
stuck somewhere?