Xantia a/c blower fan relay??

[MalcolmBrown]

My 1999 Xantia LX HDI has climate control which either works perfectly (icy cold after being re-gassed this year) or not at all with no heater blower and the a/c light not illuminated. Sometimes when it is playing up the a/c light goes on for a few seconds when turning on the ignition leading me to suspect a faulty relay.
I have pulled out all of the relays I can reach in the area beneath the fuse box, but was puzzled (I did this on a day when it was working) that the a/c seemed to work even when they were unplugged (excepting the one which evidently controls the diesel injection as pulling out one stopped the engine from starting though it turned over on the starter- this was a green one which had clips on the side). The only ones I haven't managed to move is a large orange coloured one which looks fragile and is stuck firmly to the board and a blue one which seems to be attached to a wiring plug separate from the main frame which mounts the other relays and is so close to the floor that I can't properly reach it.
Power is reaching the fuse (no21) even with ignition off but there is no power reaching the motor plug under the glovebox.
Everything else (including the heated rear window, which I understand was on the same circuit on earlier cars) works. Spraying the ignition switch (I couldn't face dismantling it) with switch cleaner hasn't helped either.

Does anyone know which relay actually controls the heater blower? Any suggestions gratefully received as my glasses don't fit well enough to drive with the windows down!

[citroenxm]

Have you actually checked the connection on the red plug on the blower motor itself??

These can degrade and cause a bad connection on the blower... the plug is easilly accessable under the glove box after removeing the fabric covering..

[MalcolmBrown]

Yes I have, no power to that brown plug sadly. Most unfortunate to fail in the hottest weather we have had for about five years!

[citroenxm]

The blower speed works opposite to contary belief..

3v should give it full speed 6v half speed and 12v stopped from what ive worked out... im sure thats how it waorks.

Fortunally ive never had blower issues on mine to need to look into it further..

[RichardW]

It's green I think, and the last one, or second to last, under the carpet panel above the pedals. You will probably find that the switching current has gone astray - there is a joint in the wire somewhere that fails. There is a long thread by D Hallworth that explains it... If you bridge out the power terminals where the relay is, then the fan should run - I had to run in a new supply to mine about 4 years ago - I just picked up the switched side of the ignition and piggy backed it onto the switching side of the relay. No problems since I did it (80k miles perhaps?).

[MalcolmBrown]

Curious. When the system was running OK I pulled that green one out- the one that has the black clips at the side- and the a/c light still lit but the car wouldn't start.
Assuming that I eventually find the correct relay- where did you pick up the switched side of the ignition to wire it back in?

[Old-Guy]

Relay identification on Xantias is very difficult. There is no such thing as a standard layout by model year, and/or variant. Don't believe any printed layouts you may find. It seems that each individual electrical fitter at the factory had his own ideas as to what should go where. Colour is of limited help, there's a fuller 'explanation' here.

[RichardW]

Malclom

I don't remember the relay being clipped in... it was the only 35A one in there (but then mine is a poverty spec Forte!). I took the feed from under the steering cowls - you will find that there is a brown connector going to to the ingition switch with 2 red wires on the ignition switch side (and 1 red and a thinner brown(?) one from memory on the car side). This used to carry all the current on MK1 cars, but was modded on Mk2 cars to take the load off the switch. I just tapped into the switched side, stuck a fuse in (just a blade fuse with spade connectors taped to the steering column) then ran the wire down the back and tapped into the feed wire at the relay - there was just enough room to get in behind the relay to do this. It's only carrying the mA switching current for the relay.

[MalcolmBrown]

That is really helpful thankyou. Mine too is "poverty spec" LX, which I think is pretty similar to the Forte. I don't mind the lack of Cd players/rear electric windows etc. if the climate control works!
From the post above your latest it looks like I can leave the inaccessible blue relay alone as from the colour key it is the wiper delay relay??

[Old-Guy]

.....it looks like I can leave the inaccessible blue relay alone as from the colour key it is the wiper delay relay??

Yes.

[Xantidote]

"I can leave the inaccessible blue relay alone as from the colour key it is the wiper delay relay?

I think so - I have a note from an old post I once came across on the Forum, that the blue relay is to do with the wipers (S1 cars)

[MalcolmBrown]

I have investigated further. Blue relay is definitely wipers as can feel it clicking when they are on. One of the relays is definitely the horn. The relay I thought was something to do with the fuel injection is actually the heater relay (green one with clips at side) and there is switched voltage getting to terminals 1 and 2 but only about 6 volts. I tried bridging across terminal 3 and 5 on the socket which I assumed would make it go, but it didn't and I couldn't find any voltage across 3 and 5 with my multi-tester, so I guess something may be amis at the back of the fusebox.
I think I may have to resort to my friendly Citroen repairer...
Shame it is the hottest weather for about 5 years!

[MalcolmBrown]

Having located the correct relay and bypassed it I have power at the brown plug on the heater motor...but it still doesn't work!
I guess that there is a faulty connection or some defective transistor in the motor control module...time for me to admit defeat, car booked in to local independent Citroen repairer as I am starting to become obsessed with the problem!

[citroenxm]

If you have 12v at the blower 5 pin plug then the motor WONT GO.. reduction of the volatge will make the blower spin up - the job of the slider.. its all rather confusing really..

[MalcolmBrown]

Yes, I certainly am confused and have probably spent more time sweating in the car trying to find the fault than I would have done just driving it with no ventilation apart from the windows...such problem solving exercises are more fun in Spring or Autumn!