AC pressure equal on low and high side.

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

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Killerko
1.8 16v
Posts: 80
Joined: Sun Dec 09, 2018 2:17 am

AC pressure equal on low and high side.

Post by Killerko »

I've tried to sort the AC on the new 406.. totally expected there will be a leak somewhere, but to my surprise the vacuum held perfectly.
It was a bit strange tho, as I only vacuumed the low line, but both low and high were showing vacuum in there... so it was a bit suspicious.
I decided to try to regas it anyway.. and the compressor kicked in and the pressure was being sorted as it should be.. adding more gas until the high circuit was about 160-170psi and low was showing around 30~psi.

Cold air started to blow inside.. so I left it like that, pretty happy with the result, I switched off the engine.. checked one last time the pressure is holding as it should be and disconnected everything. Later on I went for a ride, but there was no cold air anymore :roll: as it was a bit late already I left it like that.

The next day I've connected the gauges again and the pressure was equal on both lines :| 100~psi.. so that's why the compressor did not start.. as it had too high pressure now.
Question is, what could have caused this? Could the compressor be at fault? Or could this be on the other side where evaporator is? Anything else to check?
Compressor should be easy to replace.. condenser I never even seen with my own eyes as it is burried somewhere under the dashboard lol

Further to that, there is a permanent error under BSI section in PP2000 related to the compressor.. hmm
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Killerko
1.8 16v
Posts: 80
Joined: Sun Dec 09, 2018 2:17 am

Re: AC pressure equal on low and high side.

Post by Killerko »

I did some research regarding this issue and everything is pointing to the compressor issue:

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So I will have to try either to repair the compressor or buy a new one..
suprisingly there is a massive selection of new compressors online.
On autodoc website they have 20, yes twenty different ones for my car in the price range £140-200 :shock:
https://www.autodoc.co.uk/car-parts/com ... -0-hdi-110

They are not the cheapest.. but ebay got me covered for a cheaper used one for around £70~ :lol:
Killerko
1.8 16v
Posts: 80
Joined: Sun Dec 09, 2018 2:17 am

Re: AC pressure equal on low and high side.

Post by Killerko »

I've replaced the compressor for a second hand from ebay.. added oil and added refrigerant, and still not working.
The clutch is not engaging. I start to thing the issue might be somewhere else and the compressor is actually ok...

Checked both fuses, under the steering wheel and engine bay, both ok.
Some videos suggest the relay on the BSI might be faulty that controls the compressor clutch.
Got some ideas how to test if the clutch will engage if connected to 12v from this video: https://www.youtube.com/watch?v=k8IQnkqvXIQ

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Killerko
1.8 16v
Posts: 80
Joined: Sun Dec 09, 2018 2:17 am

Re: AC pressure equal on low and high side.

Post by Killerko »

I tried to test the compressor today, the one I bought from ebay and it looks faulty.. same as mine. When 12v is applied with a tester the clutch is not engaging.. no clicking, nothing moves... also the circuit is open. :roll:

Well.. back to ebay to hunt for another 'deal' :lol:

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Killerko
1.8 16v
Posts: 80
Joined: Sun Dec 09, 2018 2:17 am

Re: AC pressure equal on low and high side.

Post by Killerko »

Finally fixed the AC.. perfect cold air again! :cheesy:

Bought another 'ebay deal' this time even cheaper than thre previous one for only £40.
But this time I went to pick it up myself and took the tester with me.. fortunately, this one was all right and clutch was clicking when 12v was supplied.

In the end I decided not to swap the entire compressor as I would have to release the refrigerant again and decided to only replace the electromagnetic coil from the compressor I bough. This way I did not have to evacuate the loop as the clutch can be opened without affecting the pressurized loop.

Now, I have 2 compressors with faulty coils that I ordered 2 replacements coils for them and will fix those as well.. (got full refund for the first one from ebay seller and he told me I don't need to send it back)
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Doggy
Mod with a 2.2 HDi, De-Fapped!
Posts: 10710
Joined: Mon Oct 13, 2008 11:49 pm
Location: Northants

Re: AC pressure equal on low and high side.

Post by Doggy »

Well done. 8)

Perseverence often pays, (unless it's me persevering).
2002 HDi 2.2 Exec Estate, (2008-12) (wonderful)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
Killerko
1.8 16v
Posts: 80
Joined: Sun Dec 09, 2018 2:17 am

Re: AC pressure equal on low and high side.

Post by Killerko »

Aaand as the heatwave arrives it broke again :lol: :roll:

I tested it and it's the coil again... it's dead.
Now I'm not sure if I just been so unlucky that the coil just broke in a week on me as it meant to be or there is some other underlying issue that kill them.

Also autodoc refunded me as they don't have the coils I ordered earlier in stock so had to reorder from elsewhere.. ebay from Poland this time...
Well, not much to do until then, just wait for the new coils and hope that I was just unlucky and there isn't any other issue.

I bet when the coils arrive it will be raining and 15 degrees lol
Killerko
1.8 16v
Posts: 80
Joined: Sun Dec 09, 2018 2:17 am

Re: AC pressure equal on low and high side.

Post by Killerko »

New Thermotec electromagetic coils have arrived from Poland! Upon closer inspection I've noticed there are some differences...
First, the cable is shorter, which made me worried a little bit as the connector would not reach it's resting place.
Then the alignment bump and hole on the back of the coil was also different from original.
Fortunately, all was good and it was just Thermotec who decided to route the cable on a different side than Peugeot which allowed them to use shorter cable. That's also why the alignment bump and hole are different to make sure the coil will snap in place correctly with cable coming out on front instead on top. I used a cable tie to secure the loose cable as the original clip with screw was no longer usable as cable coming other way.

I have also used file and cleaned the both parts of the clutch and pulley contact surfaces of all the rust etc.. as before when the AC was running it made very loud noise.
All in all.. AC is running again and this time a lot quieter and I was able to get the temperature to 5.6C before I switched off the engine. Hopefuly it will stay this way and I'm done with messing with the AC on this car :lol: (still have the newly bought exec to sort out AC on that one)

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frog
2.0 Turbo
Posts: 378
Joined: Sun Aug 24, 2014 12:18 pm
Location: Netherlands

Re: AC pressure equal on low and high side.

Post by frog »

Nice, well done. Thanks for the pics! :D
Current "fleet":
2003 406 Estate 2.0HDi 110 - 7 seater - just hit 690.000 kms :cheesy:
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.
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