Xantia air con and rev counter not working. Is there a link?

[MFHBlueberry]

The rev counter has always been intermittent and usually comes back to life during a long enough journey, likewise the a/c. I had it re-gassed last month and it's been working fine but today it didn't come on despite the fans kicking in as they should when you press the air con button.

Sometimes it seems that the a/c springs into life at the same moment the rev counter wakes up. I was just wondering if they are linked in some way. Also, can anyone give me idiot proof directions to the rev counter sender so I can give it a clean because I've also heard that it can get covered in gunge and this can make it dodgy.

Thanks in advance!

Matthew.

[citroenxm]

Can we assume Mk.1 Xantia or Mk.2 1998 LATE R reg onwards??

Mk.1 Rev counter sensor is on the side of the diff.. behind the engine.. Put the car up on ramps, slide under the car, lieing on your back look up you will see the drivers side drive shaft going into the gearbox, above that you should see a black sensor body held with a white plastic clamp clip.. IF its not covered in oil.. 1x 10mm bolt grips it.. Slacken the bolt, no need to remove it, and twist wiggle the sensor out, clean the end put it back in BUT DO NOT push it in too far!!!

What I do is start the engine, and just lighty tap it back in till the rev counter wakes up then tighten the bolt.

[MFHBlueberry]

Mk.1, yes. Could it stop the a/c from operating?

[citroenxm]

no shouldnt do..

[MFHBlueberry]

That's a shame... I was hoping it might be operating some sort of compressor cut-out because it thinks the engine isn't running, or something like that.

Will I be able to see the sensor without removing the engine tray?

[citroenxm]

Oooohhh noo .. that needs to come off

[MFHBlueberry]

Oh well... In the case I'll wait for my enthusiasm batteries to recharge.

; )

[myglaren]

Is it possible that:
a) the aircon is inhibited until the engine is running and
b) the system uses the tacho signals for the rev counter to establish that the engine is running?

[xantia_v6]

Based on a look at the XM diagrams, it is more likely that the A/C inhibit is driven from the alternator warning light circuit.

Odd combinations of things working intermittently can be caused by faulty solder joints in the fuse box under the dash.

[Chris570]

on a mk2 xantia the aircon clutch and the speedo drive share the same fuse as the CPH.

Now before you say it yes I know that if the CPH fuse has blown the car won't start, but mine did a few times (including having been parked up for a few hours)

check your fuses first

[Edhertz]

I read the above comments and thought the following might be of interest to you. I posted the following on the Peugeot forum: '1.9d 206 Rev Counter and A.C Problems' 13.4.15 - /pug forum/viewtopic.php?f=4&t=52127. Coincidence or what? Hoping there may be something common to the two ....considering that they are French and related. Not managed to crack this one yet, but given the symptoms will probably be a bad connection, exposed to the weather, possibly a ground somewhere on mine.