Adding a dual position switch to IC fan, need some wiring help?

I currently have my IC fan wired in to the ignition, but would like to add a switch so I can just turn it on when the car is off. I picked up a dual postion single terminal switch. If run the power from the battery to the swtich, then run 1 of the on sides to the relay, this will give me my on with ignition. Now where do I run the other on side of the switch to power the fan when the car is off? I was thinking, wire splice into the fan red wire after the relay, which will jump the relay and not provide back feed power since the relay is normally open. Does this sound right, just trying not to fry anything?

I have done lots of searches, but no one seems to have done it this way. The most popular seems to be the basic on/off with a switch breaking the ground.

Sorry for the crude drawing.

The wiring from the battery to relay terminal 30 and then from relay 87 to the fan and then from the fan to ground must be heavy duty wire. I would recommend 12 AWG, but you might be able to get away with less depending on what size fan you are running. Make sure that there is a fuse before the relay, preferably as close to the battery as possible. The rest of the wiring can be small wire (18 AWG) since it only carries the current for the relay coil.

You have two options for the switch. Most auto parts/electronic stores should carry both.

on-on: This switch doesn't have an off position. The fan would with be automatic (on when the ignition is on) or always on.

on-off-on: This adds a middle position so that it is possible to turn the fan off even when the ignition is on.

Hope that helps.

Vince

Ran it the way I listed above and works fine. Ran power to the center terminal of the switch. Ran the one pole on the switch to the relay power, and ran the other pole to a wire spice in the red fan wire after the relay. All 3 functions work, on with ignition, on all the time, and off. Thanks for the diagram, I am going to edit the diagram from Paul93SC I had and repost it.