What I wanted is a single switch that will allow me to (1) have a manual "constant on" fan override AND (2) have a fan disable (for deep water). I finally decided to do a little research and found a wiring diagram that I think does what I want AND has a couple of built in features that I didn’t think about. I’ve also been chatting with Joemamma, and with his help, I think we got this. If you guys see something wrong, speak up. I haven’t tried to wire it up yet.
Anyway, this first diagram is the basic diagram from another site, modified for the Polaris system. Basically, using a SPDT switch, you tap into the fan 12v wire between the stock fan relay and the fan. Current supplied to the wire, via the switch (position 1), runs to the fan…bypassing the stock relay which is controlled by the temp sensor and ECU. Thus the "constant on override".
The "extra" gizmo is the "shutoff relay". This relay is by default in the closed position…which allows the current to run through it (whether coming from the stock setup OR the override setup) and operate the fan. If you put the switch in position 2, it energizes the coil in the "shutoff relay", which opens the circuit, and kills power to the fan. Thus, the disable function. It also energizes an indicator light (ie…reminder light) to let you know that your fan is totally disabled. Plus, if for some reason, the relay fails, it’ll default closed to keep the stock system intact.
The next diagram I came up with as I looked at the layout. I was concerned about the full load of the fan being pulled through the switch when using the override function. So I added another relay between the switch and stock fan wire. This relay would basically be triggered by the switch and pull the current from a 12v source such as the battery, fuse block, etc. Everything else would work as above.
With the switch in the "off" position, everything should work as normal, through the ECU, as if none of this was attached.
Like I said, I drew this up for an 08 RZR 800, but in theory, would work for almost any machine. IT IS UP TO YOU, to verify your stock wiring harness, colors, etc. Let me know what you think.
