The cooling fan stopped working - how do I install a direct switch? on 1993 Mercury Topaz

A couple days ago my car over heated after idling for about 15 minutes. I've never had problems with this car what-so-ever until now. The fan doesn't turn on at all. I don't know if it's the relay, the temp. gauge, or the fan itself, so I'm wondering how I can install a switch in my dash to turn the fan on directly? What parts do I get, where do I get them from, how should I install and has any one else had this problem or put a switch in before? Thanks.

Asked by for the 1993 Mercury Topaz
do not add a switch fix it right , ck fans for pwr and operation, if no pwr ck relays.if needed seek a diag and rep
Globalhelper is correct! don't add an in-line or other type of switch. If it feedsback improper voltage or ground to any other system you'll end up with lots of other problems.Get the circuit/system properly diagnosed , it will be a lot less expensive in the long run. If you want to do the diagnosis and repair yourself, that's fine , but be informed about the circuit and operation before starting work.
1 more answer
check the fan by jumping it with the battery. if it runs then its either ect or the relay.