THINGS TO LOOK FOR
A thermo fan should switch on periodically when idling.  If it does not, make sure the connection to the thermostatic fan switch is okay. A fan fuse might also have gone.  Check all the fuses. Find the thermo fan relay, wiggle the relay or swap that relay with an air conditioning relay, provided that the amperage on the relays are all the same.

COST
Depending on why it’s not switching on.  If it’s the fuse it will only cost 50 cents but if it’s the thermo fan switch it could cost around $90.00.  The thermo fan itself could cost $150.00.  The wiring could cost $30.00 to correct.  The thermo fan not switching on may be bypassed or bridged at the relay or at the connection, just to get you home.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009