1987 Fourtrax 350 Fan/light issue - please help.

[briantutt]

I am trying to resurrect the old fourtrax my dad bought in 87'. It starts and runs fine but there is an issue with the fan and oil temp light that is not covered by the service manual. The manual covers light not on and fan not on but not this issue. The problem is when you turn on the ignition the oil temp light comes on and so does fan but both stay on. Everything I read says the fan should not come on and the light should go off after a few seconds. I did a resistance check on oil temp sensor at room temp and get 10,500 ohms which is what the book says it should be. I haven't pulled it to check at 212°F or 338°F but that might be next depending on what you guys think/ might be the problem. Hoping someone else has fixed this issue before. It makes sense to me that if the sensor was low resistance the control would think "over heating and turn on light and blow fan" but with the resistance at 10,500 this doesn't make sense.

[spock58]

You could have a fan control module on this Honda that is failing. I'm not sure if the older ones actually had one but all the newer ones did. Something to check into...

Lots of owners add a manual switch for turning on/off the fan to bypass the auto system that can give trouble.