Ok, I have an '85 honda civic 1.3. I know this belongs in classic honda's but response time there is not very good I'm hoping one of you guys can help me out.

Here's my post in the classic honda fourum...https://honda-tech.com/forums/showth...7#post45913947

It's hot! I need my fan

 

your fan switch is probably bad.

 

I replaced the fan switch. It was on the bottom of the radiator. My other options right now are relay, which nobody will confirm exists. And a temp sensor on the block. I would of thought the FAN SWITCH would turn on and off the fan, but I'm finding out otherwise. I really would like to know how to test these sensors and switches, so I don't have to keep buying parts I don't need.

 

the fan switch is on the back of the engine block.

 

So what is the FAN SWITCH I just replaced? It is called a fan switch, and it was located on the radiator next to the drain plug. http://www.google.com/search?q=fan+s...w=1016&bih=570

 

Yes, that turns on your fan, but it gets it's signal from the sender on the back of your block. Replace that and you should be good.

 

I looked at the one on the back of the block and it's identical to the one I replaced on the radiator. So I jumped the wires at the one on the block and turned the key on. Got nothing. Jumped the wires at the sensor I replaced on hte radiator with key on, and my fan worked. That would mean my problem is with the switch on the radiator. So I must have got a bunk one from OReilley's. I grabbed 4 used ones from the pull-a-part yard today, and two of them look ok to try. On my car these sensors are called thermo-sensors, and I think there might even be a third I saw while looking under there. It had the exact same rubber boot with two wires coming out of it as the other two. That's not even including the sending unit for the gauge lol.

I don't know about the correct terminology actually. I google thermo sensor and all the images look wrong. but I google fan switch, and that looks identical.....http://www.google.com/search?um=1&hl...w=1019&bih=570