Cooling fans not working

[Clogzz]

the missing feed

With the owner’s book saying ‘cooling fan’ fuse of 5A under the bonnet, you can be sure that’s the one feeding the coil of 1502.
There are some old topics about replacing that fuse to bring back the low speed.
The fans and their power wiring are good if when jumpering the relay sockets both fans always go to low speed from full stop.

around $700 ex-dealer

Supercheap sells bootleg fans for about $A90.
They need a different plug, and maybe tacking in with cable ties.

wondered about ... the Bitron

The Bitron output grounds the low ends of the relay coils, so cannot have a signal waveform on it.
The diagnostic pin will have 12V coming through the relay coil at rest, and 0V when energised by grounding through the Bitron.

[MikeT]

Took some time but I've managed to make a little headway with this problem. Wasn't easy with pack of printouts, haynes manual and citroen handbook in a dusty wind but here's the result so far.

To recap, we discovered a missing +12v from Pin 1 of relay 1502 (Left Fan Relay). There may be more faults in the circuit but what I've checked so far is good (and I haven't been able to to work out if this open circuit will cause the very symptoms I've described ).

I have ascertained this open circuit fault to lie somewhere between fuse F14 and Pin1 of 1502. However, according to the diagrams, between these two components the wire also feeds Pin4 of the Bitron unit and I can't determine what or where that junction might be, anyone know? (I don't even know where the Bitron is or even what it looks like. I noticed what looks like a Relay marked, "Bitron" in the engine bay fuse box).

From what I can gather, the loom runs from the passenger fuse box, out along the O/S wing, under the radiator, up into the battery area then back across to the fans - am I correct?

[DickieG]

(I don't even know where the Bitron is or even what it looks like. I noticed what looks like a Relay marked, "Bitron" in the engine bay fuse box).

The Bitron control box is located right under the N/S headlight, to gain access you have to remove the front bumper and IIRC the front panel behind it as its covered by the lip of the panel, great position,,,,,,,not!

You may be able to get to the connector plug without removing the bumper but its a right pig, you certainly won't be able to remove the unit as one of the securing nuts is covered by the panel mentioned above.

[MikeT]

You may be able to get to the connector plug without removing the bumper but its a right pig, you certainly won't be able to remove the unit as one of the securing nuts is covered by the panel mentioned above.

Yep, that's exactly what was done Bumper off, then the plastic crash protector part behind it - only to discover the fault isn't with the Bitron or it's connectors. I'll put the full details in my blog but can declare we've found the problem and Citrojim lost his bet.

[CitroJim]

I'll put the full details in my blog but can declare we've found the problem and Citrojim lost his bet.

Always happy to loose a bet Mike, I usually do

I'm waiting with keen anticipation to find out what it was!

[bosrasham123]

hi could u tell me were the cooling fan switch is on a 2006 Citroen c5 2.0 hdi vtr

[GiveMeABreak]

hi could u tell me were the cooling fan switch is on a 2006 Citroen c5 2.0 hdi vtr

You'll need to post up or send your VIN by Private Message as they are different depending on engine and model.