Air con compressor not working

[RayneR]

Hi guys, great to be back with my 406! It was months without it, as it was repairing from an accident a big one..but well not everything is working as it should.. but hell i think the electrician that was working on the car didn't know what he was working on..

First he tells me that it's probably the bsi is dead on that part because he says that on the engine bay the eletrical stuff is all good, but from inside there's no power to engage the compressor. However the compressor is working because there's a wire on the engine bay under the battery that if you feed up 12v+ on that wire the compressor kicks in.

The climate control unit i think is working fine because you press auto everything turns on the " auto " message and the " a/c" icon and the blower starts sending wind ...but the compressor doesn't kick in .


Well truth be told like 2 years ago my bsi had water ingress and the car started playing up inside like it was christmas lol, but i went right away to my garage and he sort of cleaned and dry it very well because everything started to work again normally.

Now can it be really the BSI or is any relay that probably on changing the whole dashboard could have got damaged ? It sounds a bit rubish to be something inside BSI because alot other things wouldn't work and not just the air con compressor that's my opinion.


Thank you so much, really good to be back from this nightmare.

[Doggy]

I guess your condenser was crushed in the accident and you have just had it repaired and re-gassed?

When I changed my condenser, my compressor would not cut in either. Like you I applied 12V to the clutch connector to prove it works, but I did it with the engine running. I was thinking I would let it run for a minute or so to prove the refrigeration works, then fix whatever the electrical problem was........

After half a minute or so it was blowing lovely cold air, so I turned it off and reconnected everything normally. To my surprise, it now started up as it should.

I think what happens is that the pressure sensor does not 'see' the residual gas pressure until the compressor has been running because of the non-return valve under the pressure sensor. The ecu will not turn on the compressor because it 'thinks' there is no gas. After it has run once the sensor registers the residual perssure and everything works normally.

It's worth a try.

[RayneR]

Thank you doggy, yes at first i replaced with a used condenser like almost all of the replacement things came from the same donor car ( thank god i found this guy putting an 406 for spares ).

But apparently after re gasing it would desapear almost instantly, it was the condenser that was not good but it was replaced with new one and now it's missing that compressor kicking in when we call him.

So you suggest i just let the compressor with the direct injection of 12v+ and engine running and the blower with A/C On for a while so it will make the system check up the status of the stuff ?

Thank you so much... I'm so happy i have my 406 back, love this car.

By the way do you know what's this plugs ( red,red,brown(2wires) ) ? :

And another thing my rain sensor is missing one of the suports to hold it to the mirror, they must had lost it or broken while at the repair service but i only noticed it today when i was changing the wires of the auto dim rear mirror to another location ( right on the top in the courtesy light unit and sunroof switch etc), i havent tested it if it works anyway but it does have some declination of one of the sides thats missing the holder so it's not touching the windscreen, how expensive is it ?

[benczuk]

erm, same / similar issues here. just had it re gassed. where would one connect the 12v feed to?

[Doggy]

What I did was to remove the electrical connector from the compressor, measure the resistance between either terminal and the compressor casing.
One will be almost zero ohms, the other something like 8 - 10 ohms - this is the one you need to apply 12V to. (Do it with the engine stopped first to make sure you hear the clutch operate).
Please bear in mind that forcing this on with the engine running over-rides all the safety features built into the controls, so don't leave it on. If it's going to do any good, it will do so in the first minute. My idea was to let the compressor run just long enough that someone holding their hand over an airvent could detect it cooling, proving I only had a contol issue, (I was guessing the relay in the BSI), but to my surprise it worked by itself afterwards.

[RayneR]

The wire i'm connecting the 12v+ feed is this one:



I do hear the compressor clutch engaging even when engine is stopped .. i'hav put it working and it's really sending cold air .. but hell it didn't worked afterwards i disconnect the wire

The eletrician nearby said that there's feed inside the cabin but after that the feed is lost... so in this case they could just rewire a new cable ? Or he is just saying crap and it's just a matter of the relay in the BSI ?

It's strange that he said the problem is the BSI because if it was the BSI the most probably things to happen is that a lot more stuff wouldn't work...

[jonsowman]

If you still have the dead BSIs, I'd be interested in having a look, as I'm pretty sure I can clone/virginise these

If anyone wants to donate one, they'll get a free virginised/cloned BSI in return (if I can make it work, no guarantees).

[Doggy]

This has jogged my memory - I had a similar problem on my previous 406, which turned out to be the BSI deciding there was a fault on the compressor clutch circuit, which I managed to reset and the fault never returned. It's a long shot, but may be worth a try....viewtopic.php?f=3&t=15688&hilit=BSI

[RayneR]

meh.. BSI is very expensive here also i have to change the ignition barrel and all that crap...

This is a good bye to 406, after all the things i'hav passed i didn't deserved this , probably going to sell it ...

[steve_earwig]

Did you see this? viewtopic.php?f=3&t=20800&p=207078&hili ... ay#p207078

[RayneR]

Steve, Thanks for that

I think i don't have all the electrician and hand habilitys to do all the work but i will try to do this ... The problem is that i don't know to do some things that is asking to do, like checking the continuity of whatever is asking to check lol, and some others ...

But i promise i will check this issue right after summer, now i must enjoy the return of my beloved 406 and my vacations


Love you guys for the support in our life's with the 406

[RayneR]

Well today have noticed some green liquid already dried on the engine under cover and the compressor itself and tried once again putting directly the air con working from the 12v feed and for my surprise this is what happened:

1- No more Cold Air, from the first time i posted this topic it was sending cold air but now it's not...

2- A noisy sound coming from the vents even with fan turned off but compressor engaged and engine running.

WORTH noting the A/C Radiator is new. ALSO The Pressure Switch seems to be good, no leaking.

Here's Video and some photos:

















SOOOO Despite the leakage ( ON Compressor????? ) the problem seems the BSI anyway ? Also check the vid if that sound is normal...

Thank you.

[steve_earwig]

Mine makes similar noises, like fluid squirting about behind the dash. It was much worse before I got it regassed...

Green stuff, where is it coming from? Perhaps you clean up the compressor and see where it starts coming back.

[RayneR]

Hmm probably the sound is because of no gas in the system, the green fluid came from the compressor i think... it looks like it ...when i first saw the fluid coming out was when i first did this topic some weeks ago...

i think it was coming from the compressor but at that time there was still gas in system because cold air was coming out of the vents and still the compressor did not kick in after 2 minutes of having it running alone ...also i thought that fluid was something not to bother with.

Should i first try to place another compressor?

Thank you