DIAVIA A/C: 1995 (W124) E280 Estate

[JensH]

Following previous postings about my DIAVIA after-market A/C system, often fitted to late W124s, to save the exorbitant cost of MB factory installed system, I am pleased to say that I finally managed to track down not only an appropriate full wiring diagram, but also a complete set of installation instructions, which might help anyone wanting to work on a similar system - or perhaps get it working at all...

So my hours of "creative" Google searching finally paid off, via an .ru domain, natch...

The instructions extend to 82 pages! - by and large they are very clear.

Wiring diagram is attached:


I also have a version which I have colour marked. Anyone wanting this or the full PDF, let me know and I can post a Dropbox link.

One thing this discovery has confirmed, is that, as I suspected, the R134a gas pressure in the system is Kg 0.850 (+/- 0.020) and not Kg 0.350 as was misprinted in a previous partial DIAVIA guide that I had found. So, I'll see what benefits flow from that, since my system has been under-gassed for quite a while.

Btw, my posting-absence has been down to (i) 1,000's of miles of trouble-free motoring (50k since Oct '13 acquisition) and (ii) pre-occupation with a self-build timber frame project as opposed to the usual tinkering with the motor... - that may all changes with today's MOT... followed by service at 182k miles!

Looking to convert the car from Euro 2 to Euro 6 emissions standards, so may post news on that.

Cheers,


Jens

 

[Krzysztof Matuszewski]

Hi, could I have the instructions please? Much appreciated! Thx

 

[icic]

Hi Jens

If you could link me the full PDF install manual, bulletins and anything else you have it would be appreciated! I am trying to diagnose what someone has done to my Diavia aircon and get it working again on my 320TE.

Thanks!

 

[Blobcat]

Hi Jens

If you could link me the full PDF install manual, bulletins and anything else you have it would be appreciated! I am trying to diagnose what someone has done to my Diavia aircon and get it working again on my 320TE.

Thanks!

Hello and welcome,

OP last seen Jan 2022 unfortunately

 

[icic]

Thanks Blobcat - back to my Google searching for the instructions!

 

[Richard Moakes]

Any help https://www.motor-talk.de/forum/aktion/Attachment.html?attachmentId=746678

 

[icic]

Any help https://www.motor-talk.de/forum/aktion/Attachment.html?attachmentId=746678

Hi Richard

It is similar to the bulk of what I have installed (other than the interior controls) so will have a look and see in more depth this evening!

Much appreciated!

 

[icic]

Well, I went through the manual you shared Richard and what I have found and neither is quite the same as what I have.

It is a Diavia system however and having done some digging it looks as though (A) the green wire driving the aircon compressor wasn't connected which it now is (b) the fuse next to the single relay (near the battery running from the two fans and the aircon compressor) I have, which is 30a, was blown and is now replaced (c) the suggested wiring to disable the heater and enable the aircon doesn't look quite right (the car had the loom and some other wiring replaced back in 2016 so it may no longer be connected up to trigger this to happen).

I am going to try and find the Diavia CU which should be at the end of the daisy chain cable from the three aircon button retro fitted between the dials and try disconnecting the 8 pin connector (which apparently might not be needed if the compressor has been replaced or is a newer retrofit). The aircon has been regased but it may not be to the right pressure so will also try and get that done to see if that helps.

 

[icic]

So to update!

After speaking to Webasto directly, further digging on the internet, removing the dash trim inside the car on the drivers side and working with an auto electrician the following info may be helpful to others:

- The part numbers from Diavia/Webasto equate to a modern replacement compressor which matches the specs, size, bolt pattern etc. This is a AKS Dasis 850958N (the last part is the important bit for compatible items from other manufacturers)
- As the receiver dryer needs replacing at the same time as the compressor. There are still Diavia Dryers available and the part number for these is 017049/2 and can be ordered from a number of different suppliers online. I am sure there are other options but I wanted to re-use the existing brackets, hoses in situ etc

My compressor was knackered and all the other parts of the system (relayers, controller, buttons etc were all working fine). As the dryer should be replaced at the same time I have bought the two above parts which come to just under £300. With fitting and a regas this will take my total expenditure on resolving this to around £500 and leave me with ice cold air con.

As a side note I was considering replacing the SPAL dual blower inside the car, but it is only accessible by removing the dash. A kind individual on another forum has posted a "hack" on how to do it from the engine side. This is here: https://www.benzworld.org/threads/how-to-fix-heater-blower-davia-sealed-aircon.2247522/ The only other interesting point of note is that these Diavia systems have no pollen filter. Quite an annoyance so I will also be looking at whether I can implement a solution to provide this capability when doing the blower replacement. I am considering options on how to make a better version of the "hack" that is documented on benzworld and will keep you updated on what I do if and when I replace it to complete a full refresh on the system.

 

[inniminiman]

Hi folks, I too have a 1992 320TE with the Diavia aftermarket system. or the last 10 years I've had it regasssed roughly every 18months to 2 years. However this year it has lasted 3 months so there is a leak. I also thought the drier may be partially blocked. I don't think it had ever been changed. ICIC- well done on geting the info from Diavia, but i think the drier number is 17048/1 (thats whats in my Diavia booklet). I found the exact one for sale from a firm called EcoClim in France. It arrived in days , total about £89 delivered. Even no VAT according to French law. I did have to reduce the height of its bracket as the new one has a little ridge round its centre. Most importantly it fits the connections spot on. Took it to be refileld on Tuesday and there's a big leak!!!!. The metal pipe that goes into the drier from the consenser has a section where the rubber pipe has chaffed on it, right near the bend after the preure switch take off. I felt the pipe "give" a bit when I unbolted the drier input nut, so that was where I probably had a microscopic hole before, and the strain on the pipe has made it worse. So next week it will be taken off and sent to a firm in Kettering for a remake.Trouble is the connections from the condenser seem rock hard and I bet the steel/aluminium conmbination has corrode welded itself together. I 'm leaving it so soak with mix of acetone and ATF as a penetrating fluid before a bit of heat is applied to free it off. if the aluminium breaks its a new condenser so fingers crossed.

Another thing is that my compressor is a Seiko-Seiki . SS121,. Maybe it has been replaced at some stage, but the mountins look exactly the same as the AKS one Diavia have quoted you. I did notice that the Seiko one has the top lugs nearest the mounting bracket cut off so it fits - still mounts with 4 bolts . Has anyone lse got this pump?

And lastly picking up a very old thread, I had the flashing EC light once- turned out to be the multipin connector located between the battery and the evaporator . cleaned the contacts and its been fine since,

I also have the Diavia blue booklet and parts/diagrams for the W124 200-220 16v the one with te 350g capacity printing error . If anyone wants I can copy and post them here
cheers for now, Chris (Inniminiman)

 

[icic]

Hi Chris

That's some further useful info you have there!

In all honesty I haven't opened the box to the dryer yet (mainly as I have been so busy) but hopefully it is the right one they have given me the part number for - If not my trip to have the new compressor, dryer and pump fitted is going to be a waste of time on Tuesday!

Is this the one you have purchased: https://www.ecoclim.net/en/receiver-dryer-filter/standard-receiver-dryer-filter//p225C43/detail.php

The AKS compressor seems to be a "modern" compatible replacement so hopefully the placement of those lugs doesn't make a difference (given the pricing for another "compatible" one was £300 more I would hope that is not the case!)

I will keep you updated with how things go on Tuesday!

Ian

 

[inniminiman]

Hi ys, that was the Drier. It fits absolutely fine with the exception that I had to trim a bit off the bracket to miss the little ridge round the drier.
The new condenser arrived from Germany yesterday- exactly as original. Just as well as the aluminium threads stripped off when removing the pipe nuts, even with loads of heat. At least once I got the metal pipe off the pressure switch came off with no trouble, so that's one expense saved. Just the pipes to get remade now. Did yours gas up OK?

 

[icic]

So - to cut a long story short, the compressor I was advised to purchase and fit was the wrong one!

I went back to Webasto and they advised that I needed a slightly different one, which the part number, after some digging, aligned to being a SS121DS1. This, similar to yours Chris, needed two of the lugs cutting off with a grinder to make it fit.

The system now has this compressor installed and after a re-gas to 850kg the system is now working as it should.

As side point I have ordered some retro fit cabin filters (which install below the windscreen wiper below the existing vents). These were made by an Italian company and their part number is WZ1310. This is to support with two things, firstly to provide some filtering capability without ripping out a system from a 1995/6 car (which seems like a massive pain!) and to work out whether I can improve on these by cutting down a charcoal and filter to fit in the space.

Will keep updated on progress!

 

[inniminiman]

Well done on getting it all working. I have had the metal pipe rewelded, a new nut on one one end and pressure tested. Also 2 of the flexible hoses were chafed so those have been replaced too. I got the third done as well as the advice was that after 27 years the old hoses were quite rigid and would probably be porous. Horrendous cost, but all done. The firm was Bee-Line Air Con services in Kettering. I bought the NRF equivalent of that AKS Dasis pump quoted above. Distance from lugs to the front is identical, as was the height, but the lugs were spaced further apart horizontally . Strange because that's the one AutoKlima on ebay (where I got the W124 condenser) also recommend. Anyway a session of cut and weld on the mounting bracket and slicing off the two lugs has the NRF equivalent fitted all neat and tidy with just enough clearance. All it needed was a slightly longer fan belt ( +13mm) to suit. It's going to be pumped up tomorrow so fingers crossed it works. With the exception of the expansion valve and stuff under the dash its a new system almost.

Out of interest what was the part number Webasto finally recommended?

 

[inniminiman]

Today's update- Air con now working! had my fingers crossed for hours while it was being done .The compressor is doing its stuff and the cooling fans click in and out regularly. Just in time for autumn rain and winter.........

 

[icic]

Hi Chris - I can't find where I wrote down the webasto pump number (was on a sticky pad on the front of all my other notes!) but the manufacturer ID I ended up with was SS121DS1 (which a number of companies seem to have made).

And as way of an update - the aircon has stopped working again! Looks to be a leak on one of the flexi hoses. Do you recall what the specs were of the ones you had to buy and where exactly they were located? Clearly going to have to do mine and may as well do all three!

 

[inniminiman]

Hi Chris - I can't find where I wrote down the webasto pump number (was on a sticky pad on the front of all my other notes!) but the manufacturer ID I ended up with was SS121DS1 (which a number of companies seem to have made).

And as way of an update - the aircon has stopped working again! Looks to be a leak on one of the flexi hoses. Do you recall what the specs were of the ones you had to buy and where exactly they were located? Clearly going to have to do mine and may as well do all three!

 

[inniminiman]

Hi, apologies for not picking this up earlier, hadn't looked at this thread for ages. The company that did mine is Bee-Cool ACS, based in Kettering. They have a website.https://www.bee-cool-aircon.co.uk/pipe-making-repairs/ The flexy pipes were remade using the original end fittings and cost about £200 each with VAT . You can post your old pipes to them and they'll courier them back to you. Mine were back within a week and they made a cracking job of the. Had the aircon running this week and its still ice cold. Hope that helps, cheers Chris