Whenever I get out of my car for more than 10 minutes I have to disconnect the negative battery cable just so the radiator fan will stop running. I have taken it to 2 different auto shops and they both said it was my security system, so I had the security system taken out. The problem did not go away though. Help!!

 

the most common cause of this problem is temp switch 'B'.
it is located inline of the top radiator hose/head outlet.
When the fans are running, key off, unplug the connector.

However the reason the temp switch is there is to take care of excess heat when the engine is shut down at full temp.
But the fan timer control unit should limit the fan run time.

 

Had same problem on my 91. It was that temp switch in the upper hose connection to the head.

 

lets try the easy DG first and not get your hands too dirty. pop open your hood. then key on, and turn on the a/c and make sure both fans are on to make sure your fans are working, then turn off the a/c and remove your key. then take the cover off of your under hood fuse box (the big one by the firewall), now look for the radiator fan relay and swap it with the same looking one right next to it. if it stops then it is the relay, now, swap back the relay but instead of putting it back into the fuse box bang it a little (the contact may be stuck in the relay) then put it back and see if it works -then I'd recommend replacing the relay. the other one that stays on after you key off is the engine coolant temp switch A (by the thermostat housing) after you key off, if the motor is roughly 200 degree F, the switch will close and ground the green wire telling the radiator fan control module to power the fans and cool off the motor for several minutes before shutting off. so what you do is try to ground the green wire, and turn the car on, then turn the car off, the fan should stay on for several minutes then turn off. if it does turn off after several minutes then you have to replace the switch A, if it doesnt turn off then it may be the radiator fan control module or an electrical problem. hope this helps because this is what I was going by when I had the problem. good luck.