Have tried to rewire the ignition switch with a relay as described in the forum. It does not work. When I measure the voltage on the switched feed I measure 12V+ but when attached to the relay I measure 0.127V. So looks like it is totaly gone. So now I need to find out the best workaround for the ignition switch. I saw mentioned that using the "Grey plug GR wire 1: 12V out on ignition and accessories". Is this the best solution? My 12V feed is ok, the fan is ok. The only thing that does not work is the switched feed.
Morten
Xantia '94 Aut AC
239' km
Heater fan fails with faulty ignition switch
Moderator: RichardW
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SteveG
Not knowing how good your electrical knowledge is please don't be offended if you consider I'm insulting your intelligence 
If the voltage across the relay drops to almost zero then there are only a few possible causes.
First, I would measure the voltage across the switch contacts with the engine running. If the switch is faulty you will get 12V (or thereabouts) but if it's making a good connection that will be close to zero.
My second move would be to take the feed to the switch and connect it directly to the coil of the relay. If the blower and demister now work you know you have a working relay which is connected properly and have pretty well determined that the switch is at fault.
Hope that helps
If the voltage across the relay drops to almost zero then there are only a few possible causes.
First, I would measure the voltage across the switch contacts with the engine running. If the switch is faulty you will get 12V (or thereabouts) but if it's making a good connection that will be close to zero.
My second move would be to take the feed to the switch and connect it directly to the coil of the relay. If the blower and demister now work you know you have a working relay which is connected properly and have pretty well determined that the switch is at fault.
Hope that helps
If just the relay causes loss of voltage, then the switch contact is totally cactus.
You can use wire 1 of the grey plug because it’s switched on ‘ignition’ and ‘accessories’.
The fact that it’s switched on ‘accessories’ doesn’t matter because the fan won’t spin on the accessory position because on an air-conditioned car the combined fan speed and climate control ECU board under the dash is only energised when the key is on the ‘ignition’ position, and with the engine running.
The intent is to prevent the fan from spinning when the engine is off, because the high fan current could quickly flatten the battery.
You can use wire 1 of the grey plug because it’s switched on ‘ignition’ and ‘accessories’.
The fact that it’s switched on ‘accessories’ doesn’t matter because the fan won’t spin on the accessory position because on an air-conditioned car the combined fan speed and climate control ECU board under the dash is only energised when the key is on the ‘ignition’ position, and with the engine running.
The intent is to prevent the fan from spinning when the engine is off, because the high fan current could quickly flatten the battery.
2002 C5 2.0i AL4 230,000 km 76372389
SteveG,SteveG wrote:Not knowing how good your electrical knowledge is please don't be offended if you consider I'm insulting your intelligence
If the voltage across the relay drops to almost zero then there are only a few possible causes.
First, I would measure the voltage across the switch contacts with the engine running. If the switch is faulty you will get 12V (or thereabouts) but if it's making a good connection that will be close to zero.
My second move would be to take the feed to the switch and connect it directly to the coil of the relay. If the blower and demister now work you know you have a working relay which is connected properly and have pretty well determined that the switch is at fault.
Hope that helps
thanks for your reply. The voltage measured (0.127V) was not measured across the relay, it was measured on the relay contact when the ignition switch was connected. The relay was tested with the 12V feed directly. The relay worked and the blower worked fine. So I measure 12V out from the ignition switch until I connect it to the relay, when it drops to 0.127V and nothing happens.
Morten
Clogzz,Clogzz wrote:If just the relay causes loss of voltage, then the switch contact is totally cactus.
You can use wire 1 of the grey plug because it’s switched on ‘ignition’ and ‘accessories’.
The fact that it’s switched on ‘accessories’ doesn’t matter because the fan won’t spin on the accessory position because on an air-conditioned car the combined fan speed and climate control ECU board under the dash is only energised when the key is on the ‘ignition’ position, and with the engine running.
The intent is to prevent the fan from spinning when the engine is off, because the high fan current could quickly flatten the battery.
I got a drop from 12V to 0.127V when I connect it to the relay. Looks like the switch contact is gone. My AC is manual which means that I dont have the automatic climate control. Will my fan spin when "ignition" is on?
Morten
The fan will only spin if the engine is running.
With the key set to the 'ignition' position and without running the engine, the fan will not spin.
Sure you don’t have the relay coil supplied from the switched voltage that drops with the high fan motor current ?
In most cases, the dodgy switch contact is still good for the low current of the relay coil.
There’s relevant context in this topic:
http://www.frenchcarforum.co.uk/forum/v ... hp?t=20544
And this drawing from RichardW, one of our experts of long standing:
http://www.geocities.com/tricky992002/fanmod.xls
With the key set to the 'ignition' position and without running the engine, the fan will not spin.
Sure you don’t have the relay coil supplied from the switched voltage that drops with the high fan motor current ?
In most cases, the dodgy switch contact is still good for the low current of the relay coil.
There’s relevant context in this topic:
http://www.frenchcarforum.co.uk/forum/v ... hp?t=20544
And this drawing from RichardW, one of our experts of long standing:
http://www.geocities.com/tricky992002/fanmod.xls
2002 C5 2.0i AL4 230,000 km 76372389
I have used the drawing from RichardW, and the circut layout you provided. I've checked the connections and I can't see that I have done anything different from RichardW's drawing. I will check again.Clogzz wrote:The fan will only spin if the engine is running.
With the key set to the 'ignition' position and without running the engine, the fan will not spin.
Sure you don’t have the relay coil supplied from the switched voltage that drops with the high fan motor current ?
In most cases, the dodgy switch contact is still good for the low current of the relay coil.
There’s relevant context in this topic:
http://www.frenchcarforum.co.uk/forum/v ... hp?t=20544
And this drawing from RichardW, one of our experts of long standing:
http://www.geocities.com/tricky992002/fanmod.xls
I have connected the relay as follow :
#30 = 12V feed from battery (w/fuse)
#87 = 12V out to fan
#85 = 12V to relay coil (ignition switched operated)
#86 = Earth
in addition I have 12V feed to the ignition switch, to operate switched out to #85
Let me know if this is wrong.
Today I used the fan by using the 12V feed to ignition, directly on #85, and it worked without problem. If I use the same feed via the ignition switch, noting happens. But again I will recheck to see if I have done someting wrong.
Morten
All that looks totally correct, so it must be the switch contact that can’t even handle the low relay coil current.
You can confirm that by jumping the switched wire 1 of the grey plug to #85.
If it then works, you can make a permanent fix of it.
The rear window demister timer is switched by the same contact, so if that doesn’t work either, you’ve got a second confirmation.
You can confirm that by jumping the switched wire 1 of the grey plug to #85.
If it then works, you can make a permanent fix of it.
The rear window demister timer is switched by the same contact, so if that doesn’t work either, you’ve got a second confirmation.
2002 C5 2.0i AL4 230,000 km 76372389
Can I hijack this thread 
I am also trying to get my fan to work. I tried installing the relay but the fan was silent. I have removed the fan and motor and carried out a bench test ( I tried running the fan off a 12v supply from a battery charger)....its dead apart from a very small noise from inside the unit.
The car is an air con but I would be happy just to get the fan running before the frosty mornings set in.
Is it possible to carry out any repairs to the fan motor?
ps I was getting 12v at the supply end of the fan.
I am also trying to get my fan to work. I tried installing the relay but the fan was silent. I have removed the fan and motor and carried out a bench test ( I tried running the fan off a 12v supply from a battery charger)....its dead apart from a very small noise from inside the unit.
The car is an air con but I would be happy just to get the fan running before the frosty mornings set in.
Is it possible to carry out any repairs to the fan motor?
ps I was getting 12v at the supply end of the fan.
If you have a reasonable idea on the functioning of simple electric motors there is no reason why you can't try and get it to bits - I've never done one and don't know how much is metal and how much is plastic!
If you are getting current through it - it sounds as though the brushes are making contact with the commutator. Another good test if you have a meter is to connect the meter across the terminals and turn the motor with your fingers. It should generate a small current which can be observed. The current should fluctuate - you're looking for dead patches etc. You can even listen to it with an audio frequency amplifier! If it performs these tests satisfactorily its difficult to know what is wrong with it!
What power is your battery charger? - I'd use a car battery myself as these things draw quite a heavy current, and the battery charger output is probably unsmoothed rectified DC which might cause problems (long time since I've tested one this way - and can't remember if it worked well)
Some battery chargers are of a so-called 'safety design' (I have a Halfords one) which don't work with flat batteries! - True and I dismantled this one which belonged to my Father - until something made me look at the Halfords web site and investigate its spec. In fact its ok on a nearly flat battery but won't touch a completelly flat one - and of course when I went to test it - nothing happened! Having dismantled it I thought it best to swap it with mine as I had to damage the case to get it apart!
If you are getting current through it - it sounds as though the brushes are making contact with the commutator. Another good test if you have a meter is to connect the meter across the terminals and turn the motor with your fingers. It should generate a small current which can be observed. The current should fluctuate - you're looking for dead patches etc. You can even listen to it with an audio frequency amplifier! If it performs these tests satisfactorily its difficult to know what is wrong with it!
What power is your battery charger? - I'd use a car battery myself as these things draw quite a heavy current, and the battery charger output is probably unsmoothed rectified DC which might cause problems (long time since I've tested one this way - and can't remember if it worked well)
Some battery chargers are of a so-called 'safety design' (I have a Halfords one) which don't work with flat batteries! - True and I dismantled this one which belonged to my Father - until something made me look at the Halfords web site and investigate its spec. In fact its ok on a nearly flat battery but won't touch a completelly flat one - and of course when I went to test it - nothing happened! Having dismantled it I thought it best to swap it with mine as I had to damage the case to get it apart!
jeremy
Thank god for brothers in law.....He managed to source me a fan / motor from a contact he knew.
I fitted the unit (testing it before installation) and it spun on demand. Great.
ONE problem though.........the motor spins in the opposite direction.
The original impeller is marked up as an anticlockwise rotation
The replacement is marked up as a Clockwise rotaion !!
Is there any way of changing the rotation of the motor i.e swapping the leads over ??
(I could then just swap the impellers over)
I know that it can be done on a 415v motor on 3 phase.
I fitted the unit (testing it before installation) and it spun on demand. Great.
ONE problem though.........the motor spins in the opposite direction.
The original impeller is marked up as an anticlockwise rotation
The replacement is marked up as a Clockwise rotaion !!
Is there any way of changing the rotation of the motor i.e swapping the leads over ??
(I could then just swap the impellers over)
I know that it can be done on a 415v motor on 3 phase.
If it spins clockwise and still blows the air outwards, and the outlet blows in the same direction, then it may be good as it is.
Swapping the leads will change the direction of rotation, but make sure to swap them at the brushes only, because on an air-conditioned car there’s the transistorised motor drive that’s got to keep its polarity.
Swapping the leads will change the direction of rotation, but make sure to swap them at the brushes only, because on an air-conditioned car there’s the transistorised motor drive that’s got to keep its polarity.
2002 C5 2.0i AL4 230,000 km 76372389
Finally, grey switching plug did the work to #85. Fan now works again. 
Thanks for all help.
Morten
Thanks for all help.
Morten
Clogzz wrote:All that looks totally correct, so it must be the switch contact that can’t even handle the low relay coil current.
You can confirm that by jumping the switched wire 1 of the grey plug to #85.
If it then works, you can make a permanent fix of it.
The rear window demister timer is switched by the same contact, so if that doesn’t work either, you’ve got a second confirmation.