You say you unplugged it. Do you mean you unplugged the fan motor itself, under the front bumper (more/less)?

Or do you mean the temp switch at the receiver drier? The receiver drier is the black cylinder behind the right headlight. Find two wires with spade connectors. They should be connected to a brass fitting screwed into the black thing.

1) If not, and they're connected together, there's your problem. Someone jumpered your aux fan.

1a) Undo whatever you did to "unplug" the fan; i.e. plug it back in. If it's running, disconnect the wires from each other or "un-jumper" them. Does it stop running? You're done.

2) But if they are connected to the switch (the brass thing is temperature switch) ...

2a) Plug your fan back in. I assume it starts running. Then disconnect one wire from the R/D. Does it stop? If so, you've got a bad switch. (This presumes you're not trying to run your A/C and the receiver drier isn't hot).

2b) If it runs with the wires disconnected, then you've got a bad (stuck) relay. It should be on the left fender, maybe the most outboard/rearwards, possibly under the cover. Carefully disconnect that one (it MAY be warmer than the others as a tip to help locate the right one). Does it stop now? It's a bad relay.

Post back with your results. You can buy and install either a bad switch or a bad relay easily. The R/D temp switch, unlike the pressure switch, doesn't open up the A/C system.