Combines 1680 HEATING UP

Al, Check to see if you can turn the rad fan by hand (motor not running). I'd suspect belt and_or tensioner.

To Skinnbone, I put new belts on before harvest because I thought that might have been the problem, no luck. Belts feel plenty tight. Thanks for the suggestion. I'd welcome any more ideas.

Would suggest checking the vibration dampner, have seen similar failures on IH engines. Damper hub and pulley are seperated with a rubber ring that fatigues allowing the hub to spin inside of the pulley. Check fan pulley for wear on one or both grooves. Contact your CASE IH dealer about a larger rotary screen shaft and bearings in kit form that has a larger screen mounting plate to prevent screen vibration. Many years ago there was a mod program that addressed some of these issues. Check plenum for air leaks that are not going through the rotary screen. Check the air screen brush and check to see if rotary screen is round and if the rotary screen fan still has all of it's blades

The vibration dampner is a good idea to check as said. Power wash the radiator, you could be surprised on how dirty it is.

Al is right,check the pulley on the water pump mine did the same thing and the pulley was severly worn. When the air conditioner kicked in it would slip the fan drive pulley. I replaced the fan pulley and installed new belts which solved the problem. Cost was around $110 for pulley and belts. Good luck!