1998 406 1.9TD cooling fan wiring diagram?

[ekjdm14]

As per the title, I'm looking for the wiring diagram for our 406 cooling fans. Will grab the VIN if anyone might have access to the right one.

The fault I'm chasing is intermittently the fan will turn on and run the battery flat while parked. I've a feeling this was also a common Xantia problem and maybe to do with the Bitron relay, am I on the right track there? (Seem to recall Black used to do it on occasion, but only seemed to trigger from the interior light coming on (weird) so I always caught it before it was a problem).

FWIW I can fairly reliably trigger the fan to run-on in the 406 by tapping the horn button with the ignition off. Strange feature lol

[mickthemaverick]

What is the RPO number Dan, need it to find the correct diagram, also the body shape and gearbox as I only have access to pre 2013 cars on the backup which does not have VIN listings.

[ekjdm14]

Thank you Mick, will see if I can find the RPO not sure if it's still visible as I recall it was flaky looking when we got the car. If memory serves I may have copied it in paint marker so will check at some point. Anywhere else one could find RPO other than the stamp on the strut tower? (assuming I'm even thinking of the right number!)

The car is a Ph.1 Break/sw, manual gearbox (ML5T?), fairly base model think it's an LX, no AC.

EDIT- assuming I'm looking at the right thing RPO looks like 784889

[mickthemaverick]

It is on the tyre pressure sticker on the door pillar. Post a pic of the sticker and I will confirm the RPO from it.

[ekjdm14]

It is on the tyre pressure sticker on the door pillar. Post a pic of the sticker and I will confirm the RPO from it.

Beat me as I edited, does 784889 sound plausible? Will check door sticker now. Thanks!

EDIT- last 6 on the sticker says 775580 so probably not looking at the right thing (unless not the original door, which is highly plausible also given the bodywork condition), will grab the missus' phone and try get a photo uploaded!

[mickthemaverick]

No, it generally starts with a 1 and is a 5 digit number, sometimes followed by two characters that show the country of origin

[ekjdm14]

Cheers, I'm getting confuddled somewhere then lol. I always thought the RPO was stamped near the paint code?

Photo upcoming cheers.

[ekjdm14]

Going to attempt getting the photos across from phone to laptop now, but there's no 5 digit number on either of the stickers I can see (Unless you count the "195/65" part of the tyre size on the pressure chart lol). Only other sticker is the "Reglage Compensateur" or "Compensator Adjustment" sticker on the left door.

If I wasn't confused prior then I am now.

Damn phone is acting up not sending the photos across (This is exactly why I refuse to have a mobile! They just serve to infuriate!), but I can confirm nothing matching what you were expecting on either sticker

[ekjdm14]

Finally it's worked, photos of what I have Please tell me I'm not going blind!

And the other one...

[mickthemaverick]

No you are not Dan, your car must be pre the practice of putting the RPO on that sticker. In which case I'll work out one for the year when looking for your diagram!! I'll be back in due course

[mickthemaverick]

To go back that far I invented 07823 as an RPO which is april 1998 so close enough. This is the diagram for the non A/C car of that period:

406 fan.pdf

Copied from Sedre backup

(594.41 KiB) Downloaded 53 times

[ekjdm14]

Thanking you sir Glad it's not just my eyesight then!

[ekjdm14]

So, looking at that it looks slightly different to what I expected. Not sure if the diagram is just "abbreviated" but it only shows one fan & ours has two, also the ECU is earmarked as (DW10) although probably not a whole heap of differences in the way it interacts with the fan relays.

Still looks to me like the issue is going to be a flaky Bitron since it's handling the low speed side of things, and turning the ignition on causes the ECU to "wake up" and realise the fan doesn't need to be running hence cutting the ground(?) to the control side of the low speed relay.

What's confusing me is the fact it can be triggered by the horn button being tapped. Think I need to go back into the Citroen area & dig back for posts on Bitron issues.

[mickthemaverick]

It is possible that there are twin fan diagrams as I may have got the wrong time in 1998. I'll have another poke around in the morning as I have now lost use of my dedicated PC with the backup, which uses the TV for a monitor, as the TV is now in use for more normal viewing by SWMBO !!

[ekjdm14]

No worries thanks Mick. I've a feeling after reading back in the Citroen side of the forum that it might be a bad connection due to degraded wiring but have gleaned some info to do a little checking of the Bitron unit so might be able to test a couple of things tomorrow.

Using a TV for watching television? That's a terrible use of the thing! lol