hdi cooling fan issue

[406hditaxi]

having a bit of bother and thought id call upon you guys and your vast knowledge of these things.

when i turn on my car the cooling fan comes on and doesnt switch off, no matter what the temp is and i cant for the life of me work out what it is. the fuse box has been suggested to me but i hear it needs to be coded?

could someone maybe shed some light on this one for me?

[lozz]

hi my guess -Faulty sensor /relay perhaps .
also check the wiring for breaks /chaffing,

icarnt see it being a fusebox issue my self but knowing how Great Peugeot electrics are icouid be wrong,

Hopefully someone will post some better ideas of what the fault couid be,

[steve_earwig]

The fusebox doesn't need to be coded (been asking a Ford driver? ) It probably isn't the fusebox either. You'll get the same effect if you disconnect the fan thermo switch on the thermostat housing so this switch is probably dead.

Looks like it's #9 here:


It could also be the relay is stuck closed, stranger things have happened...

#13 here:

[406hditaxi]

its a newer version of whats shown in the diagram above.

personaly i think a relay is more likely but the advice given at the citroen pugeot garage is the fuse box itself has some form of control unit built in. i didnt actually speak to the guy myself so i couldnt tell you for sure.

[steve_earwig]

Sorry, could have done with a year but not to worry. Oh lordy, looks like on a fully multiplex car the whole lot is run by the engine management, the thermoswitch is still in the same place but the fan is run from the engine ecu via the engine fuse panel, with the relay presumably part of the pack under it. None of us have had much dealings with this as generally faults don't appear in this area, however I know the fuse panel doesn't need coding as someone over on the coupé club just changed one (wipers packed up), when he pulled it out he found the relays but I've no idea what the deal is with them. Man, who designed this spaghetti?

Once more to the schematics, I can't see a relay for any of it on the fuse panel itself, so it looks like you're spared anything to do with multiplex and coding to the BSI. That relay pack though, it just looks like a pencil case in the diagrams, and at £2.16 an empty one at that.

So much for vast knowledge As I've said a few times now, I hate knowing so little about the car I drive every day

[moodybluetwo]

What happens if you take out fuse 3 from the engine compartment fuse box?

[steve_earwig]

I'm hoping the ABS stops working Fuse 4 should kill the fan. Unfortunately it'll also kill the engine management ecu. I'm open to alternatives though, there are no decent wiring diagrams apart from the rubbish in Haynes and even the fuse diagrams in the handbooks are often gibberish.

[moodybluetwo]

According to my handbook ( 2000 Hdi) fuses 2 and 3 feed the cooling fans according to model..the ABS uses fuse 11.If the relay was stuck in the fan could get its feed from there. The feeds to the BSI and ECU I believe are data and low current..I would not expect them to power the fan motor directly without damaging the boards.Would be good to know the exact model and year of car.

[steve_earwig]

If it's later than the parts diagrams then it's 07/2001 onwards.

I'm now thinking MF3 might be worth pulling...