04 SPORTSMAN 50 HO ATP OVERHEAT/ELECTRICAL FIX

11/01/21 -- spent three days trouble shooting electrical issue / overheating -- gauge
was flashing HOT ENGINE and spitting out fluid from overflow reserve. While checking out
overheating issue it decides to lose power all together with only headlights working.
Painstakingly went over every connection tracing power and ground wires and was coming up short
on getting it to run but everything was getting power and ground. I bought a new ignition tracing the short back to the ignition harness but that didnt work and decided to test the harness on the kill switch on the left handlebar and finally found the issue. The harness connections to the kill switch was corroded and I sprayed white vinegar into the harness a few times and boom the quad started. NOW onto the original overheating issue. Tested the fan (working) -- water pump (working) -- thermal sensors (working) -- radiator (flowing) -- thermostat ( turns out was not opening all the way ) I took it out and threw it in a pot of boiling water and had a meat thermometer to get it up to 180 degrees and it turns out thermostat was not opening all the way. Bought a new thermostat and radiator cap and flushed the entire system before adding new thermostat.
Added new antifreeze slowly and watched the air bubbles come up to allow system to fill up. A few times I had to shut it off and fluid would go down and I kept adding to fill up. Its a long process properly fill up antifreeze but air in the system would overheat it and you have to do it right. A long process but I learned alot about the quad during this fix