Radiator Cooling Fan

[Phil205 1 1 Cars]

The radiator cooling fan does not appear to be cutting in when the engine gets hot in stationary traffic. How hot should the engine get before it starts ?

 

Is there an easy way to test it without running the engine hot ?

 

Hoping there is a simple way to supply power, to prove the fan operates or to test if the thermoswitch is kaput ?

[marksorrento205 80]

Take the plug off the ran switch, around a 1/3 of the way up the rad. Short pin one and two and the fan should come on slow, pin one and three and it should come on fast speed iirc. Dont worry about getting the pins wrong you wont blow anything up If this works then it could be the fan switch in the rad its self. If it does not it could be wiring, fuse etc

[AndyJ 1]

(beaten to it!)

 

Pull the plug off the thermoswitch on the end of the radiator.

Looking into the plug so that you have the 2 locating indentations at the top and 1 at the bottom, use a paperclip or similar to short the leftmost terminal to either of the other two terminals - the fan should spin up with either terminal connected.

If it doesnt spin up at all, suspect a blown fuse or dodgy wiring (check you are getting 12v at the connector).

Otherwise, it could be the fan speed resistor has blown, this would also show up as the fan only running at one speed but not the other.

 

Should probably add, dont leave the paperclip connected for very long - 20 seconds or so - as it will get rather hot...

Edited August 6, 2011 by AndyJ

[Phil205 1 1 Cars]

Thanks guys.

 

I followed Mark's instructions. The fan runs on slow and fast speed, so no problem there. I cleaned the contacts of the thermoswitch before refitting the connector.

 

If there is a problem, I think it is with the thermoswitch.

 

I haven't heard the fan when sitting in stationary traffic on a hot day recently.

 

How hot does the engine have to get before the fan runs slow and can you hear it when running on the slow speed ?

 

How hot does the engine have to get before the fan runs fast and can you hear it when running on the fast speed ?

 

 

Take the plug off the ran switch, around a 1/3 of the way up the rad. Short pin one and two and the fan should come on slow, pin one and three and it should come on fast speed iirc. Dont worry about getting the pins wrong you wont blow anything up If this works then it could be the fan switch in the rad its self. If it does not it could be wiring, fuse etc

[AndyJ 1]

You'll probably be able to hear it on fast speed, mine sounds like its about to take off...

It depends what rating of thermoswitch is fitted as to when exactly it will turn on, mine kicks in at around the second notch below red on the guage and I think it is a 96 degree switch (but dont quote me on it).

How hot is yours getting? You should be able to simply leave it idling until it gets hot and look under the bonnet to see if the fan is running.

Edited August 6, 2011 by AndyJ

[marksorrento205 80]

Sounds like its the switch to me.

 

Figures from the Haynes book of lies are

 

Stage one cuts in between 82 - 86 degree C and cuts out 77 - 81

Stage two cuts in between 86 - 90 and cuts out 81 - 85

[Choppered 0]

Have you checked the connector where the fans plug in?? As i have a simalar problem myself ended up giving the connector a bit of a clean amd away it went agin so check this also