I have to hold ac button in for air con to work!

Hi,

For the air con compressor to click on and stay on I have to hold the a/c button in because when I let go the compressor switches off (no air con) but the a/c/ button stays lighted (green). This is on my 2004 C3. I want to get behind and check the a/c button connections (maybe just need to push connections) but how do I get to it? I have searched youtube and google but can't seem to find how to take the front panel off to get to the connections at the back.

Any suggestions please?

Thanks,

Nathan.

Welcome to the forum Nathan,


There is a post on getting to the various A/C control panels found on early shape C3s here


If you have a factory multi-changer you need the same tools to remove it as you do for the radio, some of these C3 Radio Removal Keys - click here.


If you have the drawer or cubby under the radio, it just needs a good tug to remove, see this post for information on getting it out.

Thanks for the reply. I removed the cubby hole thing and unscrewed the 2 screws and checked out the connections. Everything seems fine. What I have noticed is that the ac button is quite loose feeling whereas the rear demister button is quite stiff and doesn't push in and out like the ac button. The demister works fine. Also if I only slightly push the ac button (before it clicks) and hold it the ac works. The lights keep going out on the ac button side as well and needs a tap to come back on again. Should I take it to a dealer to replace the button or should I buy a replacement console and fit it myself (obviously hoping this will fix the problem).

Thanks,

Nathan.

I tried another heater control console that I bought off of ebay, and it does the same thing. If I hold the button down the a/c compressor kicks in and works, but not on its own.

Any ideas?

Thanks.

Nathan.

I tried another heater control console that I bought off of ebay, and it does the same thing

Oh, my first choice would have been the control panel button, as you tried. So, if its not the button, it sounds like a relay not latching on, that could be a faulty relay or a fault with the wiring.

I will take a look at the wiring diagram to look for the relay for you.

No sign of a relay. I think it could well be due to a lack of refrigerant in the system. The system disengages itself due to a lack or refrigerant as a safety measure.

If the system has not been serviced in he last couple of years you could need a refill - or more accurately a drain, leak check, dry and refill.
It takes a while to complete and available from F1 Autocentres (Air Conditioning De-Mist) - Book online to make sure they know you are coming in


There is some information about detecting a/c leaks in this topic (near the bottom). and a more in-depth air conditioning diagnostics on a Citroen C3 here

Thanks for the reply. I thought this too and so I got a complete recharge last Sunday. As soon as the system was charged the technician tried the air con but couldn't get the compressor to work. He couldn't work it out because the compressor turned off and on again when the button was pressed. He checked pipes, sensors etc and said everything looked ok. It was only when I later held the button in that the refrigerant pumped around and cold air circulated.

I've booked an auto electrician to take a look hoping he can solve this. Its driving me crazy!

Thanks,
Nathan.

I have been reading about BSI units and resetting them can fix weird electrical problems. Do you think this would help the weird a/c problem I'm having?

Thanks,
Nathan.

The BSI has a hand in the control of the air con, along with the engine ECU. Resetting the BSI won't do any harm and is worth a try. It won't cost anything and crosses one more thing off the list of possibilities.