I posted this in Toyota tech, but I figured I might get some help in here as well. I have a little beater 1990 Corolla that I've been driving. The thing overheated today and found out the fan isn't coming on. Is there an easy way for me to turn the fan on so that it runs all the time when the ignition is on so I can make sure that it even works? I don't have access to a meter right now, but if you can just tell me a quick way to do it I would really appreciate it. Thanks.

 

llike dave said, unplug the fan and figure out what pin is power and what pin is ground. you might have 2 power pins. one for hi and one for low. ive got mine on a switch & relay cause I have the temp sensor unlugged among other things. did you check the fuse or relay for the fan? they might be bad.

 

OK, update. I went out after dinner and after the car cooled off and started it up. The fan worked when the A/C was on immediately. So I pulled the sensor wire off the thermostat housing to see if it was doing anything and when I pulled it off a couple of times, it shut off and came back on when I put it back on. I did it a third time after a bit and the fan shut off and never came back on. I tapped the relay and the fan motor but nothing happened. I tried removing and reseating the sensor a bunch of times but it never came back on. The relay was hot as hell so I'm leaning towards that. I'm going to try it again in a bit when the car cools off again and then buy a new relay on my way home tomorrow. Hopefully that fixes it. Other than that this car is rocking. It looks like shit, but I have ice cold A/C and it gets 25 mph. It's paid for the tires I put on it already in one week of driving it.

 

The fan will always come on immediately with AC on......not sure if you kow this.

 

Yeah, it wasn't earlier. So I let it cool off for an hour or so and tried it again.