90 Notchback 2.3l - Cooling Fan Problems

Hi all-

I need a little guidance trying to figure out why in the heck my cooling fan won't kick on. I've searched high and low across the internet and got a couple of possibilities that might work. In the process of the internet search, I stumbled across this website/forum. Everyone here seems very helpful and informative.

Specs: 1990 Ford Mustang notchback 2.3 l. Everything is/was all stock. The car was sitting in my parent's garage for the past 18 years and we had to put in a lot of work into it. As you probably figured, a lot of the parts had rusted out. We replaced all the brakes, fuel lines, brake lines, injectors, battery, hoses, radiator, thermostat, and thermostat housing. Everything seems to be working well except for the fact that the cooling fan won't kick on for some reason. I've read multiple posts and some people said it takes a long time for the fan to kick on. I've waited as long as I could (almost in the red) and still nothing. I don't want the car to overheat and risk blowing a head gasket. Does anyone know what I can try to get the fan to work? Some people are saying I might need to replace the relay, which is located under the steering wheel.

Any help would be great.

Thanks,

Matt