Radiator fan not coming on

[rhys.l]

My dc2r is having a problem where the radiator fan will not come on. Doesn't matter how long I let it idle, or how I drive the car, the fan will not come on.

I'm thinking an issue with the engine coolant temperature sensor...what do you guys think? How can I test this is the issue before I buy one? I was thinking about wiring the fan straight to something else to make sure it is not dead, but I'm not sure what is pos and neg on the fan connector. Thanks for any help

[Benson]

Disconnet the fan switch plug. Turn the car on red's and bridge the wire on the fan switch plug

If the fan doesnt turn it, fan needs replacing and if the fan turns on, fan switch needs replacing

[rhys.l]

Thanks. Which is the fan switch plug? Is this the one that sits on the firewall side of the thermostat housing on a B18? What do you mean by bridging the wire on the plug? Do you mean short it?

[rhys.l]

This is the sensor I was referring to:

[j0nn0]

If your car is not over heating.... ? well?

Its working. >_>?

[trism]

Exactly. If the fan isn't coming on, but the temp is going above half, it obviously isn't getting hot enough.

Sent from my custard cannon like Peter North.

[Vtakk]

I have the same problem with my EJ8 civic... but my engine not seem to overheat? everythings fine..thats odd lol even if i hit vtec

[Benson]

This is the sensor I was referring to:

Unclip that plug and use a wire or paper clip to bridge the wire (i.e short the wires)

[rhys.l]

Exactly. If the fan isn't coming on, but the temp is going above half, it obviously isn't getting hot enough.

Sent from my custard cannon like Peter North.

Yeah as with Vtakk, despite the fans refusing to come on, the car will not go above its normal operating temp (just under halfway) according to the temp guage. I don't understand it at all. If the car is not overheating should I just not worry about it? Can I definitely trust the temp guage?

Cheers Benson, will give it a go

[j0nn0]

If its not over heating then dont worry about it. If you dont trust it.. get it looked at..

All he will probably do is sit in the car and pretended to be a f1 driver and floor it. Then it will go two ways from here

1. Fan will come on and you will be like
or
2. Smoke, massive explosion, earthquake, pissing in pants,

[rhys.l]

Shorted the plug and the radiator fan came on fine.

It's hard not to worry about it, that's all. All other cars I have owned have to turn on their radiator fans to maintain engine temp. It doesn't make sense this car doesn't need to, maybe it has some sort of super dooper coolant? Last thing I want is my car to blow up in a traffic jam...I might get someone to have a quick look.

I've found there are 3 parts that control the fan coming on, and the reading on the temp guage:

- engine coolant temp switch (on the thermo housing, tells fan to come on)
- engine coolant temp sensor (under distributor, measures temp coolant?)
- engine coolant temp guage sending unit (under distributor, relays message to temp guage)

Wonder if I should just replace them all...

[j0nn0]

Probably leave it alone, it works!

Same thing happpened with my car man.. I was 100% it didnt work.. since it never came on after long drives, hot days etc.

It would only come on when needed.. and apparently my car never needs it xD

But I did manage to make it come on.

Your choice man.