Fans and cooling issue

[danarthurton]

Hi guys little problem, I have recently done head gasket on my 306 1.4. It's running great and when driving at normal speed temp sits around 70 -90 which I assume is normal. However when I'm in traffic temp comes up to near 100 not in the red or anything but just seems a little high!
The fan also doesn't seem to come on. I have taken off the brown plug on thermostat and 1 fan ( the left fan) comes on. Does anyone know what could be causing the fans not to kick in? Could it be the temp sensor ( brown plug) also why are they both not coming on when engine is really hot? It does have ac and switching that on or off makes no difference.
Thanks
Sorry for essay!

[Alan_M]

Both fans should come at low speed when the engine gets to 97'C or if the AC is turned on. Both at high speed when the engine reaches 107'C, AC threshold is reached or if the circuit goes faulty i.e. pulling the brown plug off the thermostat.

When was the AC last used? Sounds much like mine, AC worked when I first bought it but it had a tiny leak where it then stopped working. I left it for a while, and I'm assuming lack of use (HDis don't tend to run very hot anyway - low speed fans are hardly needed) caused the drivers side fan to seize.

I've changed mine to a pair of slimline fans for an I/C install and they work a treat, exactly as standard.

Unplug the non-working fan and check you've got juice at the plug, but to this I think you'll have to remove the bumper. Because I couldn't be arsed to do that I pulled the non-working fan relay and bodged a 12v feed to the contacts to the non-working fan. 

There is a good guide about (.pdf) on the operation of the fans with circuit diagrams etc.

[danarthurton]

Great thanks for your input! For me it's the drivers side fan that works and the passengers that doesn't. I'm certain there not coming on on low speed. My ac leaked a while ago and never bothered with it since! So if there not coming on on low or high but only when I unplug the brown does that point towards faulty sensor or bad relay?

[Alan_M]

When you pull the brown plug, you create a fault in the cooling system which should cause both fans to come on in high speed (when switched this way, both fans are switched to earth independantly or in parallel).

When the fan is called for in traffic (your car is getting hot), only low speed is called for. In this configuration, the fans are switched in series to each other. Therefore, if there is a fault in one fan, the other won't work.

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Have a read of this.

http://www.peugeotlogic.com/workshop/wsh...fanop1.htm