Slim line fans

[cwspellowe]

Right, i'm going to be installing just the one slim fan connected to a manual switch for the hot days. What I want to know is.. is there an easy way of installing a variable speed switch in the dash to adjust fan speed, a bit like a light dimmer?

If I wired one up in series with the fan, the obvious answer would be a variable resistor to drop the voltage at the fan. Would this cause the fan to stop working if it's a single speed fan relying on 12v? What if the variable resistor was wired in parallel to the fan?

Need to look into this as I want the option of leaving it spinning up slowly for security given the weather we're having.

[swampy]

Below a certain rpm it won't provide any cooling effect at all?!
The fan has to be going at a fair rate to work and be effective!!!

Another way to do it is use the kenlow in hose switch, you can adjust this to come on at any temp from about 80 upwards, so when warm line this you can adjust it downthen move it up In winter

Also allows you to run a manual on dash switch as an over ride aswell

[cully]

you can control the speed of a 12v magnet motor with a PWM motor controller of the correct Wattage
but like has been said pointless at too slow of speed as no cooling effect

[londondan86]

Why not just rip the loom out of a standard set of fans and use the cars existing supply?

[Eeyore]

Why not just rip the loom out of a standard set of fans and use the cars existing supply?

I would probably be doing this. If the fan needs to come on then it needs to be on. Itd be nice to have it controllable but as said above it needs to be going a fair wack to make any difference!