Vauxhall Corsa B (1993 - 2000) - 1999 1.0 Radiator fan not cutting in

Honest John Back Room » Technical matters
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Mon 3 Nov 2008 18:03
1999 1.0 Radiator fan not cutting in - Vintage wine
The cooling is working OK in normal use, but when the coolant temperature rises into the read on teh gauge, e.g. when stuck in traffic, the radiator fan does not come on.

I have just brought the car. The previous owner obviously had an issue as the radiator thermostat plug was missing. I have:
- Put a new plug on
- Replaced the thermostat
- Checked when the plug terminals are shorted the fan does comes on.
- Double checked the plug is firmly into the themostat

Any ideas, anyone, please?
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Mon 3 Nov 2008 18:20
1999 1.0 Radiator fan not cutting in - Screwloose

By "thermostat" do you mean the thermoswitch for the fan?

If so and the fan runs if the terminals are bridged; then either the switch is faulty, or the coolant isn't flowing sufficiently fast at idle to heat it up.

Try connecting the old switch and then immerse it in a mug of boiling water with the key on. It will need to be actually boiling.
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Mon 3 Nov 2008 18:30
1999 1.0 Radiator fan not cutting in - andyjarv
>The cooling is working OK in normal use, but when the coolant temperature rises into the read on teh gauge, e.g. when stuck in traffic, the radiator fan does not come on.<

Did you mean Red on the gauge, in winter months and especialy the cold spell we've just had I'm suprised the gauge goes into the red even in traffic, most cars I've owned had never needed the electric fan in cold weather and in warmer weather only when sat idleing for long periods of time. I'm not an expert but I would think there are other problems within the ooling system as well, perhaps an expert could come in here.
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Tue 4 Nov 2008 19:19
1999 1.0 Radiator fan not cutting in - Vintage wine
Thank-you both, Screwloose and Andyjarv.

Your combined wisdom is pointing to the coolant pump or maybe the engine thermostat. I'll check them out.

Are there any easy ways to detect a faulty pump? I mean it is obviously working to some extent.
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