I have a 97 civic dx and the radiator fan isnt coming on. I changed the thermostat and the cooling fan switch but still nothing. When i unplug the connector that connects to the cooling fan switch and put a paper clip between the two plugs and turn the key on the cooling fan kicks on (something I learned from here ). Also when the connector is plugged in to the cooling fan switch and I turn the a/c on the cooling fan doesn't come on but the a/c fan does. Does this mean that the cooling fan switch i got was bad or should I bleed the air out again (I've tried this at least two times). Any help would be appreciated because I live in California and its still hot here so I would like to use my a/c without having to worry about overheating, which is does now if i turn it on.

 

If you jump the fan switch and the fan comes on then the switch is bad.

 

Or possibly the cooling system has air in it and needs to be bled.

Edit -- sounds like the OP bled the system. Was it done like this:

Bleeding the cooling system may take 20-30 minutes.

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push/turn the dash heater lever/**** to MAX heat. Fan need not be on.

3) Follow the directions in the diagram below

 

First thing when you idle is the car temp gauge going past 1/2 way up?

If not the fan will not come on, will only come on as needed.

Also, when the AC comes on the rad fan does not come on automatically.

 

If the needle rises above halfway, then the engine is overheated. That's a different problem.

The radiator and condenser fans are separate circuits.

 

The needle should go up about a third of the way, make sure the system is bled properly before you do anything else. It could take up 30 mins to do it properly

 

Hardwire your own fan switch?

It should sit right at half as stated by ron not "1/3"

 

My point is it will not come on until it hits a certain temp. if it is not running hot, there is nothing to worry about.

 

My point is that you don't want to spread incorrect information suggesting that the radiator fan should not turn on until the engine overheats.

We'd need more information to assess whether the failure of the fan to run is normal or abnormal.

 

so did you put water in the radiator or not?

 

I never said overheat, I said certain temperature it will then come on to cool down the engine.

 

It's hard for me to interpret this^ as anything else but misinformation.

 

my car has the same exact issue. it is possible there is air in the system.

 

I did all that but I didn't park the car on an incline. I just got home from school so I'll try that and get back to you but the directions say the fan should come on twice, when I tried to bleed the air out on a level surface the fan never kicked on even when the temp got over half

 

The fan doesn't kick on after the half way point so in heavy traffic I was close to the red before I realized and turned the heater on high and pulled the car over to cool down. It doesn't go past half when im driving only when im at a stop light for a long time or in heavy traffic

 

No. I have it filled with a pre-mixed coolant but I have never put water in my radiator.

 

Mine did this once..guy i bought my car from filled overflow resevoir and not radiator

 

You must have added coolant to the radiator during the bleed, right?? See diagram I posted.

Never let the temp gauge get close to the red zone or you risk destroying the engine.

As mentioned, if you unplug the fan switch on the thermostat housing and short the 2P connector with a jumper wire, does the fan run continuously with the key in ON(II)? Does this prevent the overheating at idle? If so, replace the fan switch.

 

nvm

 

Yea, because you're using the air to act as the fan. When you're stuck in traffic, you got no air going through the radiator. Im saying its the fan switch..

Kev

EDIT- Listen to Ron, he knows his **** when it comes to electrical diagnosis.

 

I'll replace the fan switch and bleed it again this weekend and get back to you guys. Thanks so much for all your help and input.

 

Do the test before you replace. The switch is a common problem but there are other possibilities.

 

Beat me to it.

Diagnose it before you go out and spend your money.

Kev

 

I think you misread what Ron was saying, you should reread what you were talking about! Hardwiring a switch for the fan is straight ghetto, why not just do it right so you dont have to worry about it.

 

I have the same issue, it is random, goes about 3/4 up then when I start to drive it comes back down. I have a new radiator, the fan seems to come on late at times, I have bleed the system and added coolant.

I am not sure if the rad fan switch can go intermittently bad.