2 stage cooling fan control

BottleFed70 · Post by **BottleFed70** » Wed Mar 15, 2006 10:08 pm

Hi guys,

Is there anything stopping me from using the port settings in megatune to fun a 2 stage cooling system?

I'm thinking of using the FIDLE output to drive a relay for the primary fan at a coolant temp > 190*. Then use the Accel LED to drive a 2nd relay for the secondary fan when coolant temp > 200*.

Can the output from the Accel LED drive a 12V automotive relay?

Thanks

wagon · Post by **wagon** » Thu Mar 16, 2006 3:45 pm

I cannot see any reason the accel output won't work for a second fan - but - I doubt that little transistor will be up to driving a relay (except for tiny ones). You will need a bigger transistor, perhaps a small plastic pack darlington or something. You will probably have to mount it in the proto area, too, because the holes for that little transistor are very close together and small.

Enjoy.

Kendall.

BottleFed70 · Post by **BottleFed70** » Thu Mar 16, 2006 3:56 pm

wagon wrote:I cannot see any reason the accel output won't work for a second fan - but - I doubt that little transistor will be up to driving a relay (except for tiny ones). You will need a bigger transistor, perhaps a small plastic pack darlington or something. You will probably have to mount it in the proto area, too, because the holes for that little transistor are very close together and small.

Enjoy.

Kendall.

Thanks Kendall,

I'll dig through some of the MSNS-extra documentation and see if I can't find a circuit for adapting the LED output to drive a relay. It's been a long time since I've build any circuits involving transistors (highschool).

-Kalvin