'53' 406 heater fan stopped

[AndyIreland]

Hi Guys
I have a '53' 406 and the heater fan stopped a couple of days ago. What's the proper way of checking for where the fault is? I can't see any fuses that need replacing, it could be wiring, motor, regulator, connections on the switch, BUT where do I start.
Please make your explinations dumb-dumb proof, for me!
Andy

[AndyIreland]

I've been looking into this and so far this is where I'm stumped:

1 The ac/air recycle/demister on the controls are working
2 Fan speed selector working (checked with multimetre)
3 No power to fan motor (fuses ok, motor works when disconnected)
4 The controls board is blowing its bulbs
5 Central locking has also stopped (could be key battery)

What next?

[Decca]

I haven't a clue what a '53' 406 is. I'm assuming it's a D8 (first series)

re the central locking... do the doors lock when you lock a front door directly?
this will prove the central locking control unit is powered.

When you say the motor works when disconnected.. do you mean the motor spins when powered externally? say when connected with quick connect leads


Decca

[Clogzz]

The 406 heater fan is the same as on the Xantia.
The usual fault is the ignition switch going intermittent because of the high fan motor current.
There’s a modification with relay to take the current off the switch:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=24786

[np]

I haven't a clue what a '53' 406 is. I'm assuming it's a D8 (first series)
Decca

'53' is a 2003/2004 model on a 53 reg plate,so series 2

[Cavo]

Hi - I've got the same problem with a Yr99 406 HDI. Checked the fan and controls - they are all functioning okay. The ignition switch has failled. Stuck out in Germany at the moment with no haynes manual and insufficient German to explain what I want to a mechanic so looking to do the classic relay modification myself.

Unfortunately the feed on the 406 does not appear to be the same as the Xantia. I need some guidance on with wiring for a PUG though in order to pick up the right feed for the blower and avoid problems with the fan affecting the lights etc... See attached picture for the wiring layout.


Wire A: Live Feed to Ignition Switch - Yellow
Wire B: Live Feed to Ignition Swith - Red
Wire C: Common Return (to earth?) - Blue
Wire D: Feed to Fuse Board (first ignition stage power supply) - Orange
Wire E: Feed to Fuse Board (second stage power supply) - Yellow
Wire F: Feed to Fan Blower Fuse (currently giving approx 0.3V DC) - Red
Fuse G: 40amp Fan Blower Fuse

I reckon I can take the relay coil feed from Wire F and take locally to ground.
A new wire is required from the relay output to the blower fuse required.

Which Feed should I spice into to get power to the relay?

Thanks
Andrew

[AndersDK]

Since the relay is to replace the ignition switch contact set, you should splice into one of the live feeds to the ignition switch, feeding the relay contact set.

Be safe : Remove the negative battery terminal while you work on the wiring

[Cavo]

Thanks AndersDK. What I am not sure about is which of the two feeds would be the best to splice into...and can't figure it out without the wiring diagram. I recall Mandrake expressing problems with the fan power varying with blinkers, dash lights and brake lights , so assume choosing the correct feed matters.

(Got the wire. Got the relay. Got the crimps. Got 8" of snow to kneel in )

[Cavo]

All done and we have heat again. Took the feed from the Red wire and the relay switch from the Orange. No problems with interference from any of the other electrics and the relay doesn't get at all hot.

Thank you.