09 te450 spewing coolant

Was riding with my 7yo girl (more like idling) on a warmer day. and my right foot started getting warm. Noticed coolant spewing on my foot. I took off, and ran at a faster speed for a bit to cool the bike off and all was well, but during all this the fan never came on.
The fan works, it comes on for a few seconds when the key turns on.
I haven't changed out the rad cap. I probably should, I know.
Any way... has anyone put a switch in-line for this fan?
My little girl likes to ride, but doesn't get to excited when daddy just runs off for a bit!

I put a toggle switch inline to turn the fan on manually, sometimes forgot to switch it on in the tight stuff.