I know its a bit colder this time of year, but even when I let the car idle for 15 minutes or more the cooling fans do not kick in, even though the temp gauge is well up towards the high end of the scale. On another car I once owned, there was a away to force them on by unplugging a connector and shorting two pins - does anyone know how it could be done on this car?
BTW the car is not overheating at all, i'm just concerned that if and when needed they won't be available as they may have failed or seized.
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Radiator fan switch try a new one un plug and short the pins to see if the fans spin?
Normally found on the rad or coolant hose outlet search around for a mutiplug with 2 wires.
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It is probably either the temperature sensor on the head or possibly a faulty relay or dirty relay contacts. The sensor should be in the thermostat housing, if there are more than one it will probably have two wires connected to it, pull the plug off and short the pins together.
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The cooling fans on these do not have a dedicated rad fan or thermo switch.The circuit operates via the engine control unit coolant temp sensor.Do not be tempted to short or power up any wiring otherwise serious damage to the engine ecu may occur.You could try disconnecting the coolant temp sensor located on the t/stat housing.This will put the fans into default mode and should run within a few seconds.Also if the car has working a/con,then the fans should start up on slow speed after the a/c is switched on.hth
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try disconnecting the coolant temp sensor located on the t/stat housing.This will put the fans into default mode and should run within a few seconds.
You mean the one on the top of the t'stat that also sends data to the ECU, rather than the one on the bottom that drives the temp gauge in the instrument cluster?
Also if the car has working a/con then the fans should start up on slow speed after the a/c is switched on.hth
Thank you, it does have A/C so i'll try all the above at the weekend. I also have the location and details of the relays involved, so i'll give them a pull and clean them up with some servisol switch cleaning spray and make sure they are all seated back tightly.
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Yes,the one on top.The sensor at the bottom is for the temp gauge in the pod.hth
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I followed the advice given above, and found that i could force the fans on by unplugging the top connector, but despite idling for abouthalf an hour and occasionally revving the engine up, the fans just would not start on their own. The dashboard gauge never registered more than about half way, certainly nowhere near overheating.
I also removed, cleaned and refitted the relevant relays in the engine bay, and the same for any plugs i could reach on the engine cooling fan circuit. I noticed that switching on the A/C also failed to start the low speed fans, and from what I read below on another website, that would prevent the A/C from starting:
"To cool the refrigerant in the condenser you need a certain amount of airflow. To get this the main cooling fan normally comes on when the AC is demanded. If the fan does not come on the AC will be deactivated"
So, could a failed (open) thermostat be to blame for all this, or is the A/C not working completely unconnected with any of the other problems (namely, no fans coming on yet engine still running cool)
Edited by softopdriver on 14/12/2009 at 09:54
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Just to ad to my reply above, I did not hear the A/C compressor start, nor did I see or hear the expected fluctuation in RPM when switching on the A/C
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By disconnecting the engine coolant temp sensor you have proved that the fan circuit is ok.If the a/c is inop then the fans will not cut in.I suspect there is no fault with your car,the fans will only cut in when the gauge shows around 3/4 sweep.hth
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The Engine and fans are fine, your aircon is knackered tho. Probably needs a top up or it has a leak.
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The Engine and fans are fine your aircon is knackered tho. Probably needs a top up or it has a leak.
Would low A/C refrigerant cause the compressor to fail to activate then? If so, is it worth getting one of those 'top-up' cans from a motor spares stockist, or better to go for a Kwik Fit type place for a top-up? With the ambient temperatures at the moment, should the compressor still be kicking in when I demand the A/C?
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