That's what I was thinking, but when I rode it on labor day the fan kicked on and off. I cleaned it and now nothing. Thanx for all the help in advance.

 

Also when I twist the left handle bar light switch/starter module it loses all voltage

 

Check the connectors at the switch and the wiring down into the steering post area. Could be a bare wire or could be problems in the left control switch itself.

 

I have a new to me switch on the way. Gonna check wires and ohm's tonight.

 

I can't seem to get this sensor to read any ohm's

 

Well the sensor will not read any ohm's. When the quad is running the lights flicker, if I touch the light/start box on the left handle bar the lights will dim or brighten or go off all together.

 

Sounds like double trouble. Replace the sensor and see if the left control switch you ordered works ok.

 

Not to disagree but when I bought my 2001 500H.O used it had a dead battery , I just used the pull rope for the first month until I got around to buy a new battery ,but everything on the ATV worked OK.

If your buying a rad sensor go to a auto parts store and tell them you need one for a 84-88 Nissan Maxama or a 86-89 Stanza, they work , you just have to splice your old plug end onto the end to the wire.

Did you put 12v to the fan wire to make sure the Spal Fan did not die?

 

Fan runs when I run 12 Volts to the plug.

 

Give the rad sensor a try.
If it's a air lock your top rad hose will be hard and hot while the lower hose will be cooler and soft.
(Or the other way around, I forget now)
Point being,
They should be both hard and hot. after warm up.