Ok...first, I did all the searches and came up with a lot of useful information and diagrams but I never found what I am looking for...here is what I am trying to accomplish.

Like many others I am wanting to be able to turn on and off my Single Coolant Fan by the flip of a switch. I want to do this by splicing into my Coolant Temperature Switch... it's the Green/White wire that goes into my Fan Relay. This part I have been able to accomplish fairly easy.... ran a new wire out to the engine bay, spliced into the Green/White wire, tied the other end to a toggle switch which has one side tied to ground. Turn the switch on and my fan turns on... turn the switch off and it is once again controlled by the CTS.

Now I want to use a +12V Lighted Toggle switch...

I figure that I will need a +12V relay.... tie one the pins on the "switched side" to ground and the other to the wire I have spliced into the Green/White wire. Apply +12V and Ground to the other side of the relay, energize the relay and the "switched side" will close thus pulling ground into the Green/White wire and my Fan will turn on.

I thought that this was simple enough but I tried the following diagram and it did not work...



When I flip my lighted switch to the "ON" position it will light up but the relay will not energize and close the "switched side".

The relay is your standard "automotive relay" with the pins labelled as in the diagram (85,86,87, and 30/51). The relay itself does work as I tried applying +12V and Ground directly to it and it energizes the relay fine just that when I put the switch in series with it, it will not energize.

The lighted switch has a +12V pin, Ground pin, and a pin that when +12V is applied to it will keep the light on at all times opened or closed (did not use this pin)

What am I doing wrong here? I don't want to run a direct +12V switch to the fan, there must be a way to run it like I have described (unless someone tells me that it cannot possibly be done)

If someone can point me in the right direction here I will be more than willing to write a tech article on it complete with diagrams!!

Someone must have this done....

 

I will post the proper schematic later... wasn't using my lighted switch properly.

Works like a charm now.

 

I feel kind of dumb... but hey I figured it out with the help of my buddy....

My lighted switch (I would imagine all lighted switches) have three connectors...

1. +12 volts
2. Ground
3. Accessory

What I failed to realize is that when +12volts and ground are applied to Pins 1 and 2 there is a full +12 volts present on Accessory Pin #3. When this was applied to my 12 volt relay it energized the relay and closed the Switch Side of the relay. One side tied to ground and the other to the "Green/White" wire and the relay energized my fan relay turns on and my fan comes on.

I decided to put in a small inline fuse as well, probably not needed as there is little current draw through the lighted switch and relay coil but I figured it can't hurt whenever you are connecting +12volts to anything "not stock"





I am going to install another 12 volt light in my dash somewhere which will be connected to the CTS Green/White wire as well... it will come on whenever ground is seen on this wire, whether I apply the ground using the relay or if the CTS applies ground. I will post a schematic of this as well when I get it done.

Email me if you have any questions