View Full Version : Question for Dave Neilbert about fan switch:

06-02-2004, 10:06 AM
I think im going to use Dave's diagram for controling high speed and low speed fans. Im not going to use the thermostatic switches, but i want to use regular pushbutton switches...i read in a previous post that all I need to do in order to wire this is replace the thermostatic switches with regular switches in the diagram. Is this correct? I sort of modified your diagram to show this (which i have attached below). Now, if my understanding is correct all of the regular functions of the fan will operate the same way as designed by factory, but i will also be able to control them through the two switches. I would have to push the lo-speed fan switch ON, and to turn on the high speed, i still need the low speed ON and push the high speed switch correct? Also...and just to double check...doing this wiring will not have the low speed fan on all the time correct? I really dont want that...i dont like running my car cold and having the low speed fan on will take longer for the car to warm up. Thanx for any info !

original diagram:

David Neibert
06-02-2004, 11:35 AM
Yes, it would work by putting switches in the place of the controllers, but I don't know why you would want to go to all that trouble when the controllers are only $20 each. You mentioned using push button switches, and most of them are momentary (only work when pressing like a purge for nitrous) so if you go with push buttons instead of a rocker or toggle, make sure they are the continuios type.

I think the high speed switch would still work with the low speed off because the relay has an independent power supply and ground, but doing that would draw more amps than you want and will be hard on the fan motor. So always turn on the low speed first and when you turn on the high speed it will automatically turn the low speed circut off.

If your planning to use switches that illuminate when turned on, you will need and indepentent power supply for the light, because the controllers are just completing the circut by grounding or removing the ground.


PS: Dave Dalke (XR7Dave) was the one who figured this out and drew the diagram, not me.

06-02-2004, 05:19 PM
David, thank you for your reply. First, i meant to use rocker switches.....not push button ones...that was my mistake. Secondly, I thought about using the thermostatic switches, but i like the fact of having direct control over when to turn them on or off. Also, thanx for the clarification about turning the low speed fan first...i read about that so i'll always turn on the low speed first. Also, I am planning to use some type of light to indicate that a switch is on. I dont know yet if i will use a switch that actually lights up or if I will use an LED next to the switch....im trying to keep a somewhat stock look for the switch pannel on the ashtray. Regardless, as you mentioned, i will need an independent power source. What do u recomend?

David Neibert
06-02-2004, 08:37 PM
What do u recomend?

There is a small panel under the dash and I think the radio gets power from there, I just tapped into one of the wires that only had power when the ignition was on.

BTW, you do understand that the thermostatic controllers have a knob that you turn to select the temp you want the fans to come on. So you do have the control to change fan settings, just not from inside the car. You can set them so low they are always on or so high that they never come on and the EEC stock settings control the fans.


06-02-2004, 10:36 PM
I'll look for that pannel...as far as the thermostatic switches, yeah....i actually have a kit with one of those switches, but like I said I rather have the switch option right there at the tip of my hands.

06-05-2004, 10:09 PM
Where did you get the thermostatic control switch from? I'd like to do the mod using these switches.

'93 SC

06-07-2004, 09:32 AM
I got a kit from autozone that included one switch and wiring. It was like 17 dollars. I believe taht is the kit that is used to convert from a clutch fan to an electric fan,so ask for that.

06-07-2004, 04:55 PM
How would you make a clutch fan an electric fan? Or do you mean when you change out a clutch fan and replace it with an electric fan? Kind of hard to make a clutch fan electic when it is run by the water pump. Just want to make sure we're on the same page


06-07-2004, 05:06 PM
Nick, my apologies for the misunderstanding. As far as i know there is no way of 'making' a clutch fan electric. What I mean was converting from a clutch driven fan to an electric fan...ofcourse, by replacing the fan its self with an electric unit.