I have a 91 prelude si 2.1 with manuel trans and a/c. The fuses and relays are good. I am having cooling fan issues. I just bought this car, so any issues are ones that came with the car and I'm just now finding them. When I turn the key on, none of the fans come on. If I turn on the a/c, both fans come on. I had to replace the radiator, it was cracked and overheating. I also replaced the cooling fan temp. switch that is mounted at the bottom of the radiator and I replaced the thermostate. When the temp gauge comes up to half way and all the way to hot, the cooling fan doesnt come on, ever. If I turn on the a/c, both fans come on and cools the water and the gauge comes down to "normal", half way between hot and cold. Before I replaced the radiator, I was suspect that one reason the cooling fan wasn't coming on was because of the cooling fan temp switch. I used a piece of wire to complete the circuit and both the fans would come on. Why isn't the cooling fan coming on by itself? And, is the cooling fan supposed to come on with the key in the on position prior to starting the car?