Engine Fan

[denguy]

Does anyone know at what coolent temp the radiator fan kicks on?

[melgar]

Engine Fan

90C or 207F

[Bert]

Does it really matter? If your car is an EFI the thermosensor is a threaded brass device just to the left of the thermostat housing and has one wire going to it. If you unplug it the fan will run non-stop. I don't know how available or how expensive these things are if you're contemplating purchase of another.

[denguy]

Thanks, Melgar, for the simple answer to a simple question.

[Damkid]

Does it really matter? If your car is an EFI the thermosensor is a threaded brass device just to the left of the thermostat housing and has one wire going to it. If you unplug it the fan will run non-stop. I don't know how available or how expensive these things are if you're contemplating purchase of another.

Some people like their fans to run the way the factory designed them too

Personally with my setup it was just easier to have it run constant

[drddan]

My fan runs non-stop, but it is hooked up. Why is that?

[twopass]

My wifes cars fan ran even when cold so I put new sender in the water neck,the old sender was bad .
At least when the sender failed the fan came on instead of overheating the engine.
If you use teflon tape it will not ground and the fan will run,so just use a small bit of pipe dope.

[Pu241]

My fan runs non-stop, but it is hooked up. Why is that?

My wifes cars fan ran even when cold so I put new sender in the water neck,the old sender was bad .
At least when the sender failed the fan came on instead of overheating the engine.
If you use teflon tape it will not ground and the fan will run,so just use a small bit of pipe dope.

Twopass beat me to it!
Also will affect performance if engine is running too cool!

[Banana Bonanza]

My fan runs non-stop, but it is hooked up. Why is that?

Its built that way so if switch fails you dont fry your engine, goes into default mode with fan on all time. The way Festiva fan switch is wired is very good Idea. When I transplanted a 1.6 Mazda engine in my Festie, the switch on that engine works the normal way and doesnt work with the Festie relay wiring setup. The Festie switch had got broken during swap and instead of hunting up new one (the Festie switches are expensive), I bought a universal relay and wired it like every other fan switch is wired.

Oh and if the fan switch fails and you cant get new one, you can splice into upper radiator hose with metal tube and use just about any easily obtainable switch. You have to use generic relay and rewire for it as it most likely wont be backward switch like the OEM Festie one.



Like this only when I've done this on various cars, I just homemade my own out of a piece exhaust pipe with hole drilled in side and a pipe fitting welded over hole. Then got a generic $10 switch from local parts store. Watch out not all use common size threads. Need the fitting to match the threads on the switch.

I dont think it probably hurts anything running fan constantly (seen lot people do this, especially when they are too cheap to replace clogged radiator), but I dont like it. Just noise if nothing else. I prefer fan go on and off appropriately and be controlled by a relay. And a new radiator for a small car is not that expensive, lot cheaper money wise and time wise than replacing engine.