Heater fan control disc

crb · Post by **crb** » Tue Jan 03, 2012 12:33 am

Hi All,
I've stripped down my heater controls in the car - usual non operational fan speed control - getting ready to have a clean and do the wiring mod. I popped the white disc off and was giving it a wipe over and noticed that I'm missing any form of contact on the back of the disc

Can anyone give me a clue for a fix or what it should look like, I didn't see anything fall off it?

Also the earth contact (no. 3) for the fan controls is defunct, but at least the relay works when connected to earth giving a super fast fan.

Many thanks
Colin

citronut · Post by **citronut** » Tue Jan 03, 2012 7:50 am

the wiper/contact is very small and from memory it only lays in between the white disc and the PCB, so can fall out when you have your back turned,

the usual fault is the speed control resistor/board, which is in the fitted in the N/S rear face of the fan houseing,

regards malcolm

crb · Post by **crb** » Wed Jan 04, 2012 12:16 pm

Thanks Malcolm, can't find the contacts for the back of the disc anywhere in the car!

The fan runs really well when connected to the panel lighting earth circuit. I'll have another play at the weekend.

Cheers

Post by **Defender110** » Wed Jan 04, 2012 12:40 pm

crb wrote:Thanks Malcolm, can't find the contacts for the back of the disc anywhere in the car!
The fan runs really well when connected to the panel lighting earth circuit. I'll have another play at the weekend.

Cheers

Well surely if the fan is now working off the lighting earth the little contactor bridge must still be in there then to make the circuit?

EDIT:

I have a spare heater back that I will pull apart and try and upload a picture of the bridge for you (it is only tiny as Malcolm has said)

crb · Post by **crb** » Thu Jan 05, 2012 4:18 pm

Hi Kevan,
i was shorting it out rather than using the controls - wanted to see if the fan motor was OK or not
Cheers
Colin

scooters · Post by **scooters** » Thu Jan 05, 2012 7:28 pm

the bridge is about 5mm across and is a hoop of brass with a tang at 12 and at six, it is slighly bent at a 20 degree angle and on each tang is a small nipple (fnarr fnarr) the bend in the hoop gives the tension to hold it in place and one nipple runs along the outer contact on the PCB the other on the inner - it is a very easy bit to lose and may have fallen into the innards of the central console.

I will have a look as I might have a spare ring - I'll come back to you tomorrow.

BTW it will be easier to source a new PCB rather than the ring itself - I don't know if Citroen still stock them but the white knb and the conducter ring seem to come with the PCB.

I do not think it would be too tricky to fabricate somthing more suitable - I would suggest the brushes from a hornby model train could be fabricated to a better design - or some cunningly bent conductive brass.

Post by **Defender110** » Fri Jan 06, 2012 12:32 am

Hi Colin

Hopefully here are 2 pictures of the 2 different types fitted (Eledasa & Chausson) to give you an idea of what you are looking for. Sorry for the poor quality, they were taken on my phone but do zoom up quite well to show the bridging contacts.

crb · Post by **crb** » Fri Jan 06, 2012 11:34 am

Kevan, scooters you are stars - that is just what I needed to know - many thanks. I can confirm that their are no nipples on the back of my disc (ooeer matron!

)
Cheers
Colin

Quick edit - mines the Eledasa