I did a search on this and didn't see anything that seemed close. Could be I'm looking at this problem the wrong way.
I noticed this back when it was quite a bit hotter but I have a 95runner with 3.slo. Prob is that the electric cooling fan has only run while going down the freeway at 60+ mph never sitting in traffic or a stop light. I would think this would be just the opposite?
I'm still new to the Yota thing so this is a newbie question.
So am I off base or should the opposite be happening?

 

You're right it should be the opposite. How do you know its running when your aon the freeway? Can you hear it? Wires off the fan should lead to a thermo switch. I don't know how it could make itself go backwards.

 

Yes you can actually hear it switching on and off. First time I heard it kinda freaked me out. I kinda figured that it got power through a thermo switch but I haven't dug into it very far. Maybe someone on here has had something like this happen????

 

It sounds to me like your fan is hooked up wrong. Perhaps when the engine spools up at highway speeds the fan reads that as an increased load due to the AC coming on and then turns off again when you drop rpms?? That thermo switch should come on when you get to operating temperature and stay on until it cools off.

Have you checked the wiring? It might be something as easy as having two wires crossed at the connections maybe?

That fan should be running it's butt off when sitting at a light as this is the time when you have the least amount of air flow.

 

I would think it would either run or not run. In this case I'm not sure? possibly the thermo switch is reverse logic ?

 

Do you have a problem with it overheating during stop and go driving around town, when the fan is not running?

 

are you talking about the AC fan? if not who installed / what kind of electric fan is it? stock fans are mechanical...

 

It appears to be -- or I should say I have assumed it to be stock. There is a mech fan connected to the --end of pump shaft ? The fan in question is in front of condenser coil and I have always assumed it to be stock. This may not be true. As far as I know it has never gotten hot in traffic. The A/C has always blown ice cold air. That is why this seems to be a big mystery. The answer may be as easy as a botched install of an aftermarket fan ????
Like I said this is my first Toyota and I have only had it for a few months --anything is possible.