Okay so I have a 94 Civic that I was told needed a coolant flush. In the process of flushing the coolant, I discovered my radiator fan isn't activating like it should. I tested the fan (which works), replaced the relay, radiator fan switch, and coolant temperature sensor, and the fan still won't kick on.

Any other ideas on what the issue could be? Heat gauge on the gauge cluster doesn't get above 1/3 between Cold and Hot.

I'll be working on this issue later today. Any thoughts or comments before then would be greatly appreciated.

 

are you reading the pids from the computer and the fan is not clicking at the temp your sensors indicates it should? or are you just not seeing it click on? if it is not over heating what makes you so sure it does not work? it only clicks on when it needs to...

 

I suspect the dash gauge is inaccurate, as the radiator is quite hot. Hot enough to evaporate water dropped on it. I mean, I knew radiators were hot, but my understanding is you're only going to be boiling the radiator fluid if something is wrong... I'm not hearing the fan click on, and as my car is a 94, there's no OBDII to pull codes off of. I let the car idle for 20+ minutes, and even took it for a quick spin, and no action on the fan.

 

If you suspect the cluster, replace. If it is not getting hot it is probably working though. I never see my fan come on and thought it wasnt working but once in a blue moon im there and it happens. all i can say is i wouldnt assume it isnt working if everything looks fine and you just havent seen it. But from your info just swap the fan switch and thermostat.

 

I had the same problem with my 99 civic. Wasn't able to fight out the problem. So what I did was buy a part from AutoZone that let me hook up a wire from my accessory fuse under the dash and run it directly to my power wire on the radiator. So everytime I turned the car on. I got power to the fan and when I turned te car of it did as well.

 

It's really not that complicated. The thermo switch grounds the wire to the relay in the underhood fuse box. The other side of the relay coil is connected to the ignition. Thus if the ignition is on and the thermo switch is closed, one side of the relay coil has power and the other side ground, so the relay pulls in. That closes the circuit from the fuse (live all the time) to the fan motor.

 

I had mine set up to run when the car was on for a while to try and fix my over heating. It works okay but so loud >_>

 

Turtlegrip, thanks for your input. I'm pretty sure the gauge is good, and I took the thermostat out to test. The thermostat is good, so I'll just put it back in, watch temps, and wait for the fan to eventually kick in.