Radiator fan question

[Blossey]

My radiator fan had previously been set so that it turns on immediately the ignition is switched on and it continues for 2 minutes after ignition switched off.

Local garage had to rewire my electrics as some b*gger ripped mine out when they were trying to break in and silence my alarm. My fan now acts like a normal fan (ie. only comes on when at set temperature).

Anybody able to tell me how to put it back to how it was? I know it was something simple like just swapping a couple of wires over but I'm not too hot on car electrics.

Thanks

[dicky]

U shouldnt need to have the fan on all the time! It can affect ur fuel consumption and emmissions.

Wot ur mechanic would have done is bodged it and conected the fan to the power supply bypassing the fans thermostat switch.

The only reason it turned off after 2 mins was cos, in the senario that the fan was conected properly and if the engine is hot enought for the fan to cut in if u switch ur engine off it had that 2 mins to cool the engine relying on thermo-syphoning to cycle the coolant. Otherwise if the engine were turned off when that hot then heat would remain in the engine.

If there is a problem with overheating then try replacing the thermostat and flush the coolent system through couple of times. And use a good quility anti-freeze in a 50/50 mix.

[Blossey]

Thanks for the reply, I've not actually got an overheating problem, the problem actually stems from when the head gasket went a couple of years ago. For some reason it messed up the temperature gauge on the dashboard so it reads off the clock when its actually only say 95c. Have replaced the thermostat and rad switch already so it really is just a faulty gauge. Having an inaccurate temp gauge is not my idea of fun when I've already gone through 1 head gasket, therefore I got the rad fan to come on full-time in order to avoid any future overheating problems, having driven it like this for a while now it's actually had no noticable effect on fuel consumption or MOT emissions, although I would normally agree with your theory.

Anybody give me an answer on the correct wiring before I dive under the bonnet and start playing around?

[Fraz]

sorry but I am confused a bit so might have the wrong end of the stick here.

The temperature gauge is not worked from the fan switch it has a sensor just below the thermostat (Not sure where that is on the turbo but on mine it where the top hose goes to) which has a spade connector on it with one wire , that sensor may now be faulty, easy way to check that is to disconnect it ...then turn ignition on, if the gauge does not move in any way, earth the wire at the sensor and the gauge should go all the way to the top ...if so the gauge is fine and the sensor is at fault.

the radiator fan switch is controlled by another sensor screwed into the radiator itself (I am presuming the turbo is the same) near the bottom of the radiator below the top radiator hose. this has two wires both black (IIRC ) and all this does is supply the earth connection to the radiator fan motor.

The fan motor supply is a two pin connector that is supplied with a permanent live feed and an earth..this is supplied form the radiator fan thermostat ....to have the fan constantly running when the ignition is switched on...all you do is bridge the two earth wires at the radiator fan thermostat switch ...just unplug the connector and insert a split pin in the two connections

[dicky]

If the temps fine then just change the temp sensor.

[ecosseM]

the fan running on after you turn car of...... saw that alot on turbos, it does it to protect your engine/turbo from excess heat damage/over heating. it runs untill cars temp has dropped to a reasonable level.
would turbo timer sound right for this?
as for running all the time. hmmmm