Thermo Fan Relays,

[psi]

i made this to control my thermo fans. It may look a little complex, but it should work well.

Basiclly it workls like this:

when you start ur engine, its cold, so u don't want ur thermo's to run. thats good for the engine to warm up. When the ECU or thermal switch activates for the first time when the engine reaches operating temp, the fans gets turned on.

When the fans cool the engine and the switch is deactivated, the change-over relay puts the power through the ballast resistor. This will run the fans at half speed.. (or less, depending on voltage drop through the resistor) this will reduce the thermal cycling effect that happens with normal on/off switches.

When ignition power is stopped, the fans stop.

Any thoughts..

[GeeTR]

Nice and simple... but dammit, someone with patience should be hooking something sexy up, to a proper micro controller [ http://www.rev-ed.co.uk/picaxe/ ] or such.

Agreed, your idea would smoothen the action of a full on/off setup.

- M