Manual radiator fan switch?

Question

i bought a temporary gas saver car the other day just to get from my new job and back to home which is like 13miles... point a-b and back to a. it has alot of mods done to the engine. basically a tuner rocket (92 civic 5speed) one thing i notice was that my radiator fan doesnt come on like normal cars does instead i would have to turn the switch on in order for the fan to cool the radiator. does anybody know exactly when to turn the switch on? do i turn the switch on while driving then turn it off when im at a stop light or how do this work? lols, like i said i dont know when exactly to turn it on. i accidentaly lost the sellers # and google doesnt have the answers to my question. please help me thanks

Answer 1

Best Answer - Chosen by Voters

It is a conundrum!

If I were you I would turn it on and leave it on until you turn off the car. This won't hurt anything.

If you try any thing else your likely to blow the head gasket.

Answer 2

Turn it on when the temp gauge starts to climb above the 1/2 way mark.

Ideally I'd install a thermostatically controlled switch. If you don't keep close watch on the temp gauge you could easily ruin the engine. Additionally, electric fan systems are designed to come on even after you've parked the car in order to dissipate residual heat from the engine so it doesn't have hot spots to cause damage.

I suspect the person installed a manual switch with some idea to saving electricity or reducing work for the alternator (which takes engine power to run) but fans don't use much and it's really false economy, especially if you ruin the engine.

Source(s):

mechanic for 40 years

Answer 3

For a thirteen mile drive there is not much consequence. Normal temperatures in a car do not require the fan to run. Someone was hot rodding this car and installed this switch to prevent over heating. For a normal drive it is not needed. The cooling system handles the heat in several ways. First, by the coolant fluid. That mixture of 50% water and 50% chemicals raises the boiling point of the fluid. The thermostat allows the fluid to quickly get to operating temperature. The pressure in the system further increases the boiling point of the fluid. After all, internal combustion explosions to generate power are in the order of 2000 degrees F+. The electric fans typically kick in in a low airflow situation as in stopped in Traffic but only if a certain level temperature is sensed. Yours might work as normal. I do not know how you noticed that yours does not function like normal as you indicate. With the motor running it is impossible to hear this fan. I notice mine only after the engine is stopped and the temp is over the middle mark (2001 Audi TT Roadster). I think you are over thinking this. Are you sure you have a manual override only? If need be have a mechanic check this feature out for you. Best wishes.