Put the UTV with the front end up at a 45 deg angle and loosen the cap with the engine running and run the engine and rev it up every so often for 10 to 15 minutes. This will remove trapped air in the engine and the system. Also check to make sure the radiator is clear and the fan is coming on also make sure after it is warmed up that there is flow in the radiator if if there is no flow you need to test or change out the thermostat.....

Why not just get a new relay? If you want to run it all the time just go to the switched terminal next to the battery. It probably won't hurt anything to run it all the time (mine runs a lot during the summer months). I'd put a on/off switch on the dash so you can at least manually control the fan's operation.

I have a Rzr4 and really like it enjoy taking my family. If I had 3 little ones I would change the rear seats out with a rear bench seat from Twisted Stitch.
It is a Rzr S with more seats.

Thanks for the feedback, can I fit (qty 3) 5 point harnesses on bench seat?