Xantia blower motor woes

[Kitch]

Only just picked up my 3rd Xantia yesterday. 1996 1.9TD SX and I'm actually happy with it!
I gave everything a full work over in the test drive, especially the heater.

So I was pissed off today when it stopped working Especially with all the frost we're getting!

Its got A/C and the toggle switch with AUTO on the far left and MAX on the right.
Up until this morning, all was well. But now nothing happens; the temperature works fine, as does the adjustment of the ventilation. But the fan motor doesn't. It does come on very very briefly for a second or so every bow and then, even when selected to MAX, so I ruled out a fuse.

Any ideas? I've heard of a resistor unit but in honesty I know little about Xantias as I've always been from the BX stable The fan looks like a right nightmare to get to, is there a common fault and solution?

Thanks

[alan s]

Kitch,

Take a run through this thread.

http://208.109.104.50/forum/showthread.php?t=43977

it brings it back through this forum a couple of times, but between it all, the problem is in there somewhere. I'd suggest the posting by Clogzz as it fixed mine.

Worth doing ASAP to save the additional cost of the ignition switch.


Alan S

[Peter.N.]

The XM has a fuse box in the engine compartment, just behind the battery, with a 30a fuse that supplies the heater, this fuse can develop a bad connection with the holder, in fact it can melt! I suspect the Xantia has something similar. Otherwise, its probably the speed control transistors on the motor itself.

[Clogzz]

a resistor unit … The fan looks like a right nightmare to get to

The resistor is the voltage dropper to regulate the speed on non-aircon cars, so there isn’t one.
The fan has 3 mounting screws in rubber bushes, but you won’t need to go that far.
The fault will show up at the plug, as loss of supply between the thick red and black wires.
Dodgy plug, or ignition switch.

[Kitch]

Thanks for the advice. is the heater motor behind the glovebox?

[Peter.N.]

Yes, well sort of under the glovebox.

[KennyW]

Hi Team,

A message for Peter.N where do you get the transistors from unable to source any in my neck of the woods.

Edinburgh area.

Been on the net and the nearest place for same model France etc.

Cheers

Kenny W

[jeremy]

This subject has been well discussed on here and somewhere there is a post listing the required characteristics of the transistor and some alternatives.

Don't think its precise characteristics are important - just necessary for it to be of the right type and be able to cope with the load.

[dnsey]

RS keep them: (apologies for the long URL!)
http://rswww.com/cgi-bin/bv/rswww/searc ... &Nr=avl:uk

Mail order or trade counter - whichever you find easier.

[Clogzz]

behind the glovebox?

under the glovebox.

You remove the felt cover above the passenger foot space, then you get this, with the motor and plug at top left.

[Kitch]

Excellent, I'll have a look for that today.

One thing I have noticed though, when the fan doesn't work the heated rear screen also dies, yet when the fan does the screen comes back. So they must be linked?

[Clogzz]

Yes, they are linked in that both are operated from a contact in the ignition switch that fails due to the high fan current.
When the fan spins, the voltage out of the switch is high enough.
While it’s high enough, it can also operate the rear window demister timer, which is in fact a timed relay; 11 minutes says the book.
The current for the demister doesn’t pass through the switch, but the low relay coil current does.
When the switch contact fails, the output voltage is low.
That stops the fan, and is also too low to energise the demister timer relay.
The solution is to supply the fan with a relay switched by the ignition key, for while the switch contact still works at times.
The contact is usually still good to operate a second relay.

Worth doing ASAP to save the additional cost of the ignition switch.

To do the modification properly, you normally would have to break into the steering wheel shrouds, but it looks like many have taken the new fan supply from the cigarette lighter.
That makes the job much quicker, and you can dangle the relay inside the felt cover.
Story, pictures and maps here:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=17322

If you go inside the steering wheel shrouds, there’s this drawing from RichardW:

http://www.geocities.com/tricky992002/fanmod.xls

[Kitch]

Excellent! Sounds like thats my problem.

Just while I'm still in lazy mode though.....if I removed the fuse for the rear demister, would that help....IE stop sapping current so the fan can get all it needs?
I only ask as two out of the all the lines on the rear screen actually work, and its quite pointless.

Cheers

[SteveG]

Excellent! Sounds like thats my problem.

Just while I'm still in lazy mode though.....if I removed the fuse for the rear demister, would that help....IE stop sapping current so the fan can get all it needs?
I only ask as two out of the all the lines on the rear screen actually work, and its quite pointless.

Cheers

There's no benefit in removing the demister fuse ... it has no more effect than not switching the demister on. The relay for the demister only draws a few milli-amps anyway so it's not ging to make a significant difference to the switch current.

I did the relay mod on my Xantia estate and it only took about 45 minutes. Maplins sell a suitable relay for a couple of quid.

HTH

[Clogzz]

Alas no, because the heating current for the demister doesn’t pass through the switch.
The heating current comes from the battery through a fuse of itself, without passing through the switch, but going through the demister timer relay instead.
The current to operate the coil of the demister relay passes through the switch, but that’s comparatively very small, not anything that will ever sap the current needed for the fan motor.
The fan motor may take something like 20 Amps at high speed.
The relay coil current could be less than 1/10th of an Amp.

Edit: And oops SteveG !
Sorry, but I sent my story before I saw your post.