you would have to tap into wires to add a switch, I use regular anti-freeze 1/3 to 2/3 water(Texas Heat). I drilled 2 1/4" hole in my thermostat, some remove all together. I'm leaving my stock fan wired as is, and adding a second fan on a switch. I just remove my cap and squeeze the lower rad. hose to get air out. You'll need to do this once your thermostat is open. So, crank it with the cap off and let it get hot enough for it to open.