This diagram is for the SP1 only, and how to properly wire in a manual toggle switch. You're on your own to determine where to mount it.
This will allow you to turn your fan on whenever you please, but allows for the fan to work automatically when the switch is turned off
, so no need to worry about constantly monitoring engine temp. Even with the toggle switch on, the fan will stop when the ignition key is turned off. That's because the fan gets power from the fuse box, which is a switched power source.
I'd recommend to check all related ground points, clean and use a dab of dielectric grease.
Use 16 gauge wire for the splice, and solder the connection. You don't want any failures from those cheesy crimp/splice connectors.
On SP1, the fan uses a 10 amp fuse in the fuse box, (the forward most fuse), so maybe a toggle switch of at least 10 amp rating would work, but I'd rather err on the side of overkill. That's why I recommend a 20 amp toggle switch. I'd also recommend one of high quality and waterproof.
Big Thank You
for creating the diagram for this thread. I gave him a hand drawn draft and he got it all gussied up.