Help with A/C

Talk about the 406's electrical system, what wires do what, how to add extra functionality, etc.

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puggy1
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Help with A/C

Post by puggy1 » Sun Jun 03, 2018 11:28 am

My 2.2 Hdi Executive Estate A/C always worked uses all year round.About 5 months ago it stopped working from one day to the next.At the moment when I turn it on the cooling fan runs but the the compressor pump clutch is not engaging after the engine runs for a few minutes the A/C pipes get cold, I have checked the pump it turns OK I have checked the plug on the wiring to the pump. What turns on the pump is it the BSI I have seen the post about the relay change. Any help appreciated. PS I have had to register again as I could not reset my password .

frog
2.0 16v
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Re: Help with A/C

Post by frog » Mon Jun 04, 2018 9:09 am

Have you checked the refrigerant level/pressure? I seem to remember that the BSI will not engage the clutch of the compressor if the refrigerant level/pressure is too low.
Current "fleet":
2003 406 Estate 2.0HDi 110 - 7 seater
2001 Citroen Saxo 1.6i 8v 100

Previously owned:
2000 406 Sedan 2.0 HDi 90
2000 406 Coupé 2.0i 16v 138 - Riviera Blue

PP2000 user, can help with faults / diagnostics in the Netherlands.

Nikod3mus
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Re: Help with A/C

Post by Nikod3mus » Thu Jul 26, 2018 8:22 am

I managed to f*ck up a little bit my BSI-relay change. One of the copper rings detached from the PCB. Now I need to jump wire one of the relay pins but where? It's one of the coil pins, picture is in attachments.


Any help is very appreciated!


Another thing is that can you test the AC by simply connecting the two wires from the compressor straight to battery?
bsi.jpg
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Last edited by Nikod3mus on Thu Jul 26, 2018 11:48 am, edited 1 time in total.

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steve_earwig
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Re: Help with A/C

Post by steve_earwig » Thu Jul 26, 2018 10:32 am

No matter how much I magnify the picture I can't see any damage - is this your BSI? Looks like the pin circled has no connection this side so there must be a track on the other side. Not seeing it I can't say how to proceed but maybe if you can connect a meter to any existing part of the track and probe to see if you can find the other end? I can't imagine you could do any damage with just a multimeter but I have been wrong in the past...

If this is no help perhaps I can search for it in the wiring diagram, there is nothing for inside the BSI but perhaps you can test from the connectors into the board. Let me know as it could take a while...
Unskilled meddling sin©e 2007

2004 D9 2.0 HDi 110 Estate lhd VF38ERHZF81657352 - sold but being very well looked after.
1991 Yamaha TDM850 - fuel leaks galore!
2008 Toyota Recall4 2.0 VVTI ATM LHD JTMBH31V90D007261 - flimsy piece of crap.
1953 Matchless G3LS - It's alive!!

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steve_earwig
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Re: Help with A/C

Post by steve_earwig » Thu Jul 26, 2018 10:42 am

I'm not sure how the system would respond if you fed power to the compressor, however if the air conditioning is turned on it probably wouldn't matter unless the system is empty.

I've found the feed, wire 8060A, pin 13 on the 16-way green connector. I suppose this has a 25% chance of being the connection you are looking for...
Unskilled meddling sin©e 2007

2004 D9 2.0 HDi 110 Estate lhd VF38ERHZF81657352 - sold but being very well looked after.
1991 Yamaha TDM850 - fuel leaks galore!
2008 Toyota Recall4 2.0 VVTI ATM LHD JTMBH31V90D007261 - flimsy piece of crap.
1953 Matchless G3LS - It's alive!!

Nikod3mus
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Re: Help with A/C

Post by Nikod3mus » Thu Jul 26, 2018 11:47 am

steve_earwig wrote:
Thu Jul 26, 2018 10:32 am
No matter how much I magnify the picture I can't see any damage - is this your BSI? Looks like the pin circled has no connection this side so there must be a track on the other side. Not seeing it I can't say how to proceed but maybe if you can connect a meter to any existing part of the track and probe to see if you can find the other end? I can't imagine you could do any damage with just a multimeter but I have been wrong in the past...
Picture is just an example, not my BSI. Picture shows what connection we are talking about ja and the side of PCB which is damaged.

Other side of the PCB is still covered with the plastic cover and I understand it is not ment to be removed? At least no easy way to do it.
steve_earwig wrote:I've found the feed, wire 8060A, pin 13 on the 16-way green connector. I suppose this has a 25% chance of being the connection you are looking for...
I'm not an expert but isn't that 8060A connector the feed that goes to the AC when relay is on (yellow in the new picture)? Connector in the picture is either ground or the feed from the AC-button in the dash. Or is it ground controlled?

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steve_earwig
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Re: Help with A/C

Post by steve_earwig » Thu Jul 26, 2018 1:15 pm

Ah, so there's no way of getting to the other side, damn. I don't know how the relays are controlled (not by the button on the dash anyway, the ecu tells it to switch on) as there are no diagrams that I've managed to find, even the far more comprehensive full-mux diagrams show very little inside the BSI (although the relays it does show appear to be ground-switched).

Can you see anything with the relay removed? Or are you afraid of making even more problems... Cut a bigger hole?
Unskilled meddling sin©e 2007

2004 D9 2.0 HDi 110 Estate lhd VF38ERHZF81657352 - sold but being very well looked after.
1991 Yamaha TDM850 - fuel leaks galore!
2008 Toyota Recall4 2.0 VVTI ATM LHD JTMBH31V90D007261 - flimsy piece of crap.
1953 Matchless G3LS - It's alive!!

Nikod3mus
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Re: Help with A/C

Post by Nikod3mus » Thu Jul 26, 2018 1:56 pm

steve_earwig wrote:
Thu Jul 26, 2018 1:15 pm
Ah, so there's no way of getting to the other side, damn. I don't know how the relays are controlled (not by the button on the dash anyway, the ecu tells it to switch on) as there are no diagrams that I've managed to find, even the far more comprehensive full-mux diagrams show very little inside the BSI (although the relays it does show appear to be ground-switched).

Can you see anything with the relay removed? Or are you afraid of making even more problems... Cut a bigger hole?
OK, it seems that I must do measurements when BSI is hooked up in the car. If it is ground-switched, then either green or red connector in my picture should have constant +12V voltage and the other one is grounded when AC button is pressed.

Anyone know what is the similar relay above the AC relay? Possibly could measure that one to have comparison if it is something that could be switched on when stationary (not e.g. cruise...).

First I try to peek the other side if I see anything and you could cut the hole bigger in some directions.

New406guy
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Re: Help with A/C

Post by New406guy » Tue Aug 28, 2018 6:50 pm

Hey guys, my a/c stopped working yesterday, a day after i refilled it with freon gas. There is no 12v on the compressor's terminals. I heard that the BSI contains a relay that operates the system, but there is a few not-straight-to-the-point diagrams for my car's BSI (2003 406 1.8i 16v). Could the BSI not be giving an order to the compressor due to a mistake in the gas pressure? (Low or high?) And if no, what is the relay responsible for the activation of the compressor in the BSI?

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