91 firebird electric fan problem

i have a 1991 firebird with electric cooling fan, i will not come on so it is letting my engine heat up i tried a light tester on the plug and wires but does not seem to be getting any juice is there a relay or fuse somewhere between the plug and the fuse box, or something that i am missing. thank you for your help. V8 ?I believe the switch that tourns the fan on is in the right head above the starter.again need engine size sorry bout that the size is a 305 automatic. thank you. find the connector that hooks to that switch,disconnect it and ground it with the key on.if the fan runs the switch is bad. thank you for all your help