Xantia II aircon and climate control, Diagnostic test path

[techmanagain]

Can anyone help with a diagnostic test procedure path for a Xantia II aircon with climate control?
Alternativerly or additionally does anyone have a wiring diagram fo the same system.
I can recall this diagnostic test procedure being issued by Citroen to deal with auto gearbox problems but I'm hoping that they issued the same for the Xantia aircon & climate control. It an absolute maze of wiring, and a logical sequence of test and events should reveal any faults

[techmanagain]

I am pleased to report that my aircon is working properly now and I can report that the major fault was - as is so ofetn - the heater fan control unit. I found that there are some replacements on Ebay; I also fornd that the price seems th reflect their quality as I was only able to get a "high speed only" response when fitted. I suppose I should have known better at my tiime of life and eventualyy paid 10 timres its price to buy a genuine Citroen unit, also replaced the temperature controller (fited on the side of the passenger seat-well near the heater fan) with a second hand unit, sourced from Willie Johnston.
Noz has the alleged faulty units to work his wonders on them and (if possible, to find if they were really faulty and if so , whether they are repairable. I hope to be able to help others with advice on their aircon and heater problems in due course.
Now to sort out why the remote control on the key fob does not work the oracle and lock and unlock the doors., and replace a rear ABS sensor which has been tested and found to be erratic. Oh the joys of owning a car!

[Peter.N.]

On the XMs the most common fault is the 30a fuse/holder under the bonnet, followed by the regulator transistors on the motor, I have only had one with a faulty control panel and I just replaced it with a secondhand one and it was fine.

Peter

[citroenxm]

The non working remote fob is HIGHLY likely one of the micro buttons have sheard off the PCB board.

This is because on S2 cars they are completely surface mount, and rely totaly on the strength of the solder to hold it in place. However, they do shear off and the reason for this is because when you press the button theres a mometry delay between the press and the ECU to decide to unlock the car... So, in "Our" wizdom, we press it again harder, and then it breaks away.

I can and have sucessfully resoldered the switch's back onto the boards however, then put a blob of hot stick glue behind it to support the switch .. there is a BUT.. the but is, though I have only been sucessfull in dooing this IF the mounting points on the PCB have also NOT been ripped off the board. You will know as there will be 4 silver blob points for the micro switch...

Ill place my bet on this, or a flat battery.

[techmanagain]

Many thanks for that! Come the better weather, I shall venture out and clear the snow off the car and play with it again! I'll let you know how accurate your diagnosis was. I have few doubts - knowing you!

[citroenxm]

QUOTE (techmanagain @ January 19, 2013 12:21 am) 

. I have few doubts - knowing you!

What's that supposed to mean???

[noz]

Brian,

I have successfully repaired the older of the two regulator modules. I have tried it in the heater of my own car and it works perfectly. The newer regulator has a problem though. The speed control is random no matter what signal is sent. I suspect the transistors. However, it is not so simple to test the transistors even if you have them out in your hand. Internal to the package there are two pull down resistors which result in false readings when you try to test the transistor with a meter.

I have ordered some new MJ11015 transistors from China. They should be here in about 10 days.

Let me know if you need the reapaired one back now or whether you can wait for the second to be repaired and then I'll send both of them together.

Cheers

noz

This post has been edited by noz on January 26, 2013 06:22 pm

[techmanagain]

You have been very precise in your tests (as I expected) and I'm pleased that the older controller has proved sound.
As you may have seen, the new one was bought on ebay at about £7 so I thought it might be dubious - which it proved to be . As to its source originally, I suspect that the seller had bought a batch of test-failed units and guessed that no buyer would bother to send them back!
I am in no immediate need of the good or the repaired new one at the moment, but when a need arises on the XM or Xantia sites there will be one/two waiting. I will re-imburse you for all your effots and put them into stock. You yourself may have some needy ssoul by then!Again - may thanks!

[techmanagain]

Please send them together at your convenience. (and at my reimbusible (to you) cost>
Brian