Xsara 2.0 16v Cooling Fan

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Nick Kaarslev
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Joined: 18 Aug 2021, 16:12

Xsara 2.0 16v Cooling Fan

Post by Nick Kaarslev »

Hello im new here, but i recently bought a very nice Citroen Xsara from 1999 with the 2.0 16v engine, car runs great, only problem i have is that the cooling fans dont turn on automaticly, ive had to make a switch on the dash to turn them on myself... so i have changed the blue and brown sensor that sits on the thermostat housing, i havent been able to find the green one in store, do anyone know which one is actually the thermoswitch for the fans? ie, the one that registers when the car is hot and sends signal for the fans to turn on

sorry for the bad picture i stole it cause i was to lazy to go take a picture.
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Dormouse
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Re: Xsara 2.0 16v Cooling Fan

Post by Dormouse »

hi. Welcome to the Forum. Don't panic about the picture too much. Have you used the small "search this topic" box just above your Xsara heading of you first paragraph on this page?
wheeler
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Re: Xsara 2.0 16v Cooling Fan

Post by wheeler »

Does the fan come on when you switch the A/C on?
If i remember right both the Brown & Green are used for switching the fan on brown one for the A/C system & green for the engine management system.
My initial thoughts though are its not a sensor fault as when the sensor fails they normally fail safe & bring the fan(s) on full speed.
If you disconnect either the brown or green sensor with the engine running after a few seconds this should also bring the fans on full speed, can you try this?
Nick Kaarslev
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Re: Xsara 2.0 16v Cooling Fan

Post by Nick Kaarslev »

Thanks for the input wheeler, I tried removing both one at a time, the brown one made the left side fan spin up, and the green one made the RPMs shoot up for a quick second, but not the any fan, but that might be because i removed the right side relay and placed the wires for my switch where the relay used to sit, do you have any further ideas or things i could try to narrow in the problem causation, Thanks alot so far.
Nick Kaarslev
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Joined: 18 Aug 2021, 16:12

Re: Xsara 2.0 16v Cooling Fan

Post by Nick Kaarslev »

oh and i have tested the relays, both are working, and obviously both fans are working too, and for some reason my AC doesnt imediently turn on a fan, not sure if its supposed to i just have a memory of it doing so when i bought the car, might also have something to do with the fact i removed a relay.
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white exec
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Re: Xsara 2.0 16v Cooling Fan

Post by white exec »

Usual colour codes for the 3 coolant temp sensors on the water outlet have been
GREEN - Injection ECU input (for fuelling control)
BROWN - Coolant temp for Water Temp Contol Unit (WTCU), incl radiator fans and temp warnings
BLUE - 'Dial' (dash temp gauge).

On some later cars, the first two were rolled into one, and the engine ECU given control of radiator cooling, as well as air conditioning.
Nick Kaarslev
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Re: Xsara 2.0 16v Cooling Fan

Post by Nick Kaarslev »

Ah okay, thanks alot for the information white exec, i have really been wondering, and those wiring diagrams can get a bit confusing!
wheeler
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Re: Xsara 2.0 16v Cooling Fan

Post by wheeler »

Do do any fault finding on the system you need to put everything back the way it was first.
I think the fans should always come on as a pair on this system regardless of speed.
Also do you have the VIN available for looking up a wiring diagram?
Nick Kaarslev
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Re: Xsara 2.0 16v Cooling Fan

Post by Nick Kaarslev »

the vin is VF7**************[VIN obfuscated, can be read by forum staff]
Nick Kaarslev
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Re: Xsara 2.0 16v Cooling Fan

Post by Nick Kaarslev »

Yes i have the vin, the last 8 digits are 32866463, but the same problem occured with the relay inplace, and its a smaller operation to put it back in since i have to take the grill and stuff off, i can look at it tomorrow after work.
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myglaren
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Re: Xsara 2.0 16v Cooling Fan

Post by myglaren »

The VIN is automatically obscured and can be read by forum mods and admins only.
Nick Kaarslev
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Re: Xsara 2.0 16v Cooling Fan

Post by Nick Kaarslev »

wheeler, i plugged everything back in as it should be, then tried disconnecting the green connector on the thermostat housing and both my fans came on at full howl, but when the car gets up to temperature nothing happens, but i did swap out the sensor when i bought the car since i thought back then that it was the cause, what is more likely, that i got a defective sensor from the shop, or that its something else?