on my 86 iroc 305tpi, ive been having radiator fan problems. previous owner didnt have it hooked up. theres 2 wires coming from the fan, + and - of course. but thats it, no sensors or anything. any ideas on how to fix it? nothing else.. hard wire it but i don't want to.

 

basically starting with just a fan, and the wires. how would u guys do it

 

Easiest way would be a seperate fan controller - they sell at local parts store, run anywhere from $35 to $100+. The come with wiring instructions and all the wiring you need usually. I run a Flex-a-lite - $100 but fully adjustable temp settings and extra bells/whistles. But a basic $35 unit would do fine as well. They have a probe that goes between the radiator fins to sense temps and turn on fan accordingly.

 

Go back to the home page and look under Tech Articles. There are 2 post for this if you need more info like I did email Willie his address is listed there. I would tell you how but the instructions are in my car and I have installed the switches yet. But it is easy steps to follow.

 

If you want factory fan operation, get yourself a Haynes manual and follow the wiring diagram to see how to wire it according to factory spec. If you want automatic fan operation, get a fan controller and follow it's instructions, per camaronewbie's recommendations. If you want manual fan control, find a 20 amp hot in run source and wire it to a 12V 4 pin relay accordingly;
Pin 87 - (+) power supply to fan
Pin 30 - (+) power supply from 20 amp fused hot in run source
Pin 86 - (+) power supply from 20 amp fused hot in run source
Pin 85 - to switch (other side of switch goes to ground)

The switch functions the same as a fan controller would, allowing the coil side of the relay to energize by providing a circuit path to ground, closing the switch within the relay and supplying 12V to the fan. The fan ground wire can either be wired to the ground side of the switch, or directly to Ground. This setup allows direct control over when the fan is on, but also means you must keep an eye on the temperature gauge if you don't plan on having the switch on at all times when the car is running.
I have another thread in the cooling section about heavy duty cooling mods that goes more into this wiring setup, as well as installing additional electric pusher fans.