Rad fans not working once temp hits 97

[steve_earwig]

Neither does mine - Hdis don't seem to need them, apparently they run very cool

[teamster1975]

Please won't somebody tell me if this is any help?

Bloody marvellous Steve! Duly bookmarked!

[steve_earwig]

Maybe needs some info on the relays? Tell you what, when I pull my D8 out to register it I'll make sure my fans still work and take some pics of the little buggers.

[TehAgent]

Sorry i haven't replied in ages, misses just popped our sprog out, good thing for leather seats with a baby in the car, nice and easy wipe clean for them messy occasions
anyway, usual baby stats follow 4lb 14 oz, bit on the small size but shes lovely, named her keira and then she went on to crissened the car with baby yak.

Anyway, down to the fans. there still not working, but looking at another thread (should be the one below this one at time of posting) I'm off out to the car to have another ganders.

So.......where is this sensor plug thingy that if you unplug can kick the fans in?

PS. my fans are rigged to come on with a switch an a few wires earthed to car body, so i know its not the brushes or anything to do with the fans them selves, I've replaced and cleaned the relays that reside in the center of the fans. but still nothing. arrrggghhh

[steve_earwig]

A hearty congratulations on the new sprog!!

Umm, I know Haynes denies all knowledge of the turbo but it says on petrol models with air con the Bitron sensor is in the thermostat housing. Looks like you'll see at least two sensors there, it's not the brown one (welcome to the wonderful world of Haynes )

Oh looky, on a 405 it is the brown one and there is an ecu. Haynes just shows a double switch so what's really there is anyone's guess!

[mjb]

So.......where is this sensor plug thingy that if you unplug can kick the fans in?

Follow the upper radiator hose around and it'll end up at the thermostat housing. Round behind the housing (so facing away from you) you'll be able to feel 2 connectors sticking out the back. One's blue (closest to the engine) and the other is brown (closest to the air filter box). If memory serves the blue one is for the dashboard temperature display and the brown one is for the ECU. Unplug the connector to the brown one and the fans should spin up at full speed.

Can't remember if you need to pull the air filter box out to get at these or not, but it's a piece of cake and quite quick to do.

Unfortunately on the turbo it's not easy to change the sensors due to them facing away from you - I couldn't figure out how to change mine so I've got a spare ECU sensor lying in my toolbox

The Bitron ECU is apparently in the n/s wing.

[teamster1975]

Sorry for the off-topic, Congratulations on your new daughter Agent!

[TehAgent]

You would think that id know my way around this engine by now, considering i had a Citroen Xantia 1.9TD (lovely engine, never went wrong, it was the bits around it that buggered up), and a friend of mine had the Xantia Activa with the same engine as my 406.