Heater fan fails to work due to faulty ignition switch

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caeclyd2
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Heater fan fails to work due to faulty ignition switch

Post by caeclyd2 »

This also happened on my 95 xantia. From some good advice on this forum I changed the switch and the fan started to work again. I was rightly told that the wiring for the fan goes through the switch. Yesterday the interior fan on my 98 td estate failed to work on demand and would only work occasionally.......another new switch at a cost of £53+vat !
and the hassle of more keys etc.
Is there a way of taking the supply to the fan through another switch i.e fit a toggle switch ?
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Post by caeclyd2 »

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Clogzz
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Post by Clogzz »

:mrgreen:

If you’ve already changed the switch with barrel and key, you can put the old barrel back in to use the old key again because the switch part separates from the barrel.
There's also this from RichardW:

http://www.geocities.com/tricky992002/fanmod.xls
2002 C5 2.0i AL4 230,000 km 76372389
caeclyd2
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Post by caeclyd2 »

Thanks for the link to the wiring diagram.

Now I may be missing the point here but the wiring is still configured to include operation through the faulty ignition switch.

I am not an electrician so I might be missing the point somewhere.
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Post by RichardW »

"Now I may be missing the point here but the wiring is still configured to include operation through the faulty ignition switch. "


Correct, but instead of switching the full 30 amps or so, it is only switching the few milli amps required to pull in the relay - and it should be able to do this even if the switch is pretty far gone. If there is not enough left to pull the relay in, then you need to jump an ignition switched live from somewhere else.
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Post by caeclyd2 »

Richard w,

Many thanks fore the reply.
I am about to raid RS components for parts.
SteveG

Post by SteveG »

caeclyd2 wrote:Richard w,

Many thanks fore the reply.
I am about to raid RS components for parts.
Maplin do a suitable relay for less than £2 :)
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Post by tomthered »

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Post by jack.dempsey »

Finally got around to doing the relay mod this weekend. I also pulled the panel to replace some expired bulbs. This was possible, although a bit fiddly, without removing the steering wheel/air bag. The relay cost me a couple of quid of ebay (40 amp), and the only other expense was for some 'lucar' (spade) connectors, and some similar sized 'in line' connectors.

Chefs Hint - cut the existing wires so that you can extend both sides with 'lucar' in line connectors. On the live feed (only live when engine is running) remember to crimp a smaller cable alongside the heavy duty cable that goes to your relay switched contact. Connect this low current cable to the existing ignition switch cable (that's why we left it long enough to crimp something to), and extend the switch return cable (using an in line 'lucar') and connect to the relay coil. This then uses the ignition switch to control the relay, as shown in the various diagrams found throughout this forum. I used spade connectors that had an insulated cover - the yellow size (which is the biggest) is required. The relay was attached to a 10mm bolt near the steering column, the earth cable from the relay coil was also attached here.

Epilogue. No more jiggling with the ignition key trying to get the heater fan to start (or the rear window defroster to work). Up until doing this job the recent frosty mornings have been a nightmare to cope with. I even lost my fuel gauge by over zealous jiggling of the key- the pointer went way beyond full and stayed there for days. Now with all the above working as prescribed, my early morning stress levels are much lower than they had become, and my rear window, windscreen, and cabin temperature are now 'acceptable'. And I don't need to replace my ignition switch. Why didn't I do it months ago, when the problem was first encountered - I do not know !!
They said it couldn't be done, so we didn't bother trying!
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Post by Clogzz »

That’s definitely called doing the job ‘properly’. :)
The first modification by Citroën may have been done like that.
I modified mine in 1998, from a diagram I got from my Citroën mechanic.
The diagram was electrical only, showing what to do, but not how to do it.
So I improvised the job, with the relay dangling inside the cover above the passenger floor.
The earth of the relay is under a bolt washer in there, possibly a front guard mounting bolt.

The mechanic clearly told me that when the job was done, the diagram had to be ripped up, never to turn up again, and I duly did that.
Is that an inheritance of the Japanese ways, where failure has to be hidden and denied ? :twisted:
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