MK4 Climatronic/AC conversion - what parts needed?

[eugopnosaj 0]

Hey guys, my heater matrix went a little while back and coupled with the fact that my dials only work on the windscreen I figured since the dash has to come out anyway I'll attempt the climatronic conversion.

 

Now I've found a guy who is stripping a MK4 V6 4motion and has all the bits there so I have secured the blower box, partial loom and climatronic control box but I'm a bit lost as to everything else I need:

 

Obviously I'd need the rad, compressor (guessing this is just the pump?), pipework, condenser, evaporator...

 

I'm not sure about pulleys and the bracket, can I use the ones from his MK4 V6? Or do I need to source some other ones? Can anyone let me know what is needed as he is hoping to get it all out for me for this weekend so I can collect it in one hit but just needs a list of parts.

 

Many thanks :)

 

(I have done a forum search but nothing is definitive as to what is 100% needed)

[eugopnosaj 0]

Anyone? I know quite a few people have done this, search shows that, but there isn't anything substantial in terms of exactly what is required...

[VR-Sixy 0]

There is a quite comprehensive thread about this somewhere on here. I remember commenting about quite a while ago.

[tony_ack 0]

I'm guessing you've come across my thread and tonedef's as well, which will tell you a bit about the dash side. Here's what you need (off the top of my head...)

-Climatronic heaterbox and ducting. It should come complete with the blower fan, actuators, evaporator and possibly a matrix (though you'd be advised to fit a new one). Some people use the MK4 matrix which has slightly different pipework - I used the Corrado one and it fitted fine.

-Climatroinc control panel. You have a choice of MK4 Golf/B5 Passat (blue backlight), Skoda Octavia (green backlight) or Seat Leon (different design front panel and red backlight). I'd choose to match whatever dials you're running or planning to run. Swapping isn't a biggie as they're only about £20. Make sure you get the trim surround as it fits the Corrado perfectly and finishes the panel off nicely. Again on the surround there is a choice of walnut effect, metal effect or a kind of black rubberised trim. Go for the rubberised one if you want to keep it standardish - the rubber coating rubs off to leave a textured plastic finish which matches the rest of your dash. Keep the U-clips off your current heater controls - iirc the Corrado controls secure from behind the dash whereas the climatronic panel secures from the front - you'll understand why you need the u-clips when you fit it. The panel fits perfectly in the dash!

-Climatronic loom - this is the bit that runs from the panel itself and runs to the car loom. There are two versions with different pinouts, but they are largely the same. I think the difference is that one is designed for a high/low pressure switch on the A/C and one is designed to use a thrust sensor, but with a little manipulation they both do the same thing. You'll also need the sunlight sensor with a pig tail loom - they usually have to chop this when breaking a MK4, so make sure you get the sensor with a bit of wiring so you can splice it back in.

-Car loom - you have a choice to either make your own loom to fit the Climatronic loom (which either involves getting the right connectors to fit the Climatronic loom, or chopping the plugs from the clima loom and splicing/dicing), or do it the overkill way like I did and get the whole MK4 loom and take what you need, including all the wiring/plugs that connect to the clima loom. The benefit of that is that you also get goodies like the wiring up to the A/C, fusebox, etc and the MK4 outside temp sensor (Corrado one is incompatible with MK4 clima, so you will need a temp sender either way). Getting the MK4 loom makes it so much easier, even if it is a waste of a good loom. If you're careful, you can always sell what's leftover to someone doing an engine conversion into a MK2/Corrado without aircon.

-Compressor - I don't know whether the MK4 item will work or not, but the MK3 VR6 compressor definitely fits and is the same part no as the Corrado VR6 one. You'll need a new aux belt for a/c.

-Condenser - this is where I got stuck. I haven't really seen anything that doesn't involve chopping something or making new brackets. The MK3 VR6 rad definitely DOESN'T fit as the bottom pipe fouls the subframe. Something small and after-market may be the way to go, and make your own brackets.

Drier - I think any drier from a VW will do. I found that the MK3 one allows you to fit the hi/low pressure switch to it, so it may save some complications on the pipework

Pipework - unless you can get hold of the Corrado stuff, or Passat VR6 pipework (both very very rare), your best bet will be to head to Piritek or the like and get some made up.

Late VR fan controller - I don't know if this is essential, but Climatronic is designed to go through the fan controller. The late Corrado one is the same as that in the early MK4 V6s, so if you have a late controller you're definitely covered.

Brown engine coolant temp sender - get the Corrado item from VW, this replaces either the yellow or black temp sender on the VR (I can't remember which). Get the plugs for the loom for it at the same time, and the loom plug for the pressure switch

 

That's all I can think of at the moment - I'm sure there's more! I never got as far as finishing the A/C as other things came up at the time, but did quite a bit of research into it.

[tony_ack 0]

In case you were still going down the MK4 compressor route, there are two types - one needs a thrust sensor, the earlier one works off the high/low pressure sensor. Regarding pulley size - I have know idea, but personally I'd play it safe and get the MK3 one.

[Kevin Bacon 5]

For the condenser, I used a left hand drive OEM one from the dealer, which was only about £150 when I got it. I didn't use it for A/C but it fitted the car perfectly.

 

Since this isn't exactly a standard Corrado system either, maybe it will work for the Climatronic retrofit. Eurocarparts sell it as well if VW don't list it anymore - http://www.eurocarparts.com/ecp/c/Volkswagen_Corrado_2.9_1995/p/car-parts/car-cooling-parts-and-car-heating/air-conditioning1/air-conditioning-condenser/?222440750&1&03035ce0e0d635c412a21beaf76ebe359d4f5855&000382

 

Personally I think you're brave and mad! The HVAC system causes plenty of issues in MK4s, let alone conversions, especially the main flap positioning motor.

[eugopnosaj 0]

@ Tony Ack - Yeah I've read through your whole thread, nice work! Unfortunately it only really covered the dash side of things. Regarding your list I have (or will have):

 

- Climatronic heater box and ducting: complete box from the MK4 with everything in your list, i will check the condition of the matrix but will probably change it for piece of mind.

- Climatronic control panel: The sale includes the MK4 control panel

- Climatronic loom: Sale includes the loom and sensors, hopefully enough loom to splice back.

- Car loom: Unfortunately I will have to splice and make my own loom.

- Compressor: I will be taking the MK4 one as I was under the assumption it would be ok, shall I take the bracket also? I will source a new belt obviously. If it'll be easier I'll source a MK3 one.

- Condenser: Again taking the MK4 one, my radiator crossmember is knackered anyway so I'll either repair and modify to fit or when I source a new one I'll find a way to make it fit.

- Drier: As far as I'm aware bolts on the side of the VR rad, at least thats what I have researched.

- Pipework: I was going to take as much as I can from the MK4 and if necessary get the rest made up.

- Fan controller: The VR is a '94 so already has the late controller and twin fan setup

- Coolant temp sensor: This is a new one to me, didn't realise I needed to change this?

 

I know its a bit crazy, but other people have achieved it and I'm not afraid of a bit of work, currently also got a '69 beetle project in pieces ;)! The car is off the road and both the dash and front end need to come off anyway so I thought 'what the heck!'. If it doesn't work (or I get fed up with it), the AC part at least, I'm sure I can sell it on.

 

I also know a few guys who are good at fabricating and I can get things made through work if necessary, I will attempt to do a write up but I might not do the whole conversion this side of winter (AC to come before summer) as I want to get the beetle on the road before the year is up.

 

Thanks for your replies though.

 

Edit: If it is easier to source MK3 bits please let me know as I can let the seller know he won't need to strip them out of the car...

Edited October 2, 2013 by eugopnosaj

[tony_ack 0]

The brown coolant temp sender is used on all Corrados with aircon - it has 4 pins instead of 2. I think it provides a cut-off condition for the aircon if the water temp at the engine (rather than the rad) gets too high.

 

I think the compressor *should* mount on the existing bracket, but it won't hurt to have the MK4 one if you can get it cheap/free.

 

Let me know how you get on with the compressor, condenser and pipework. Don't forget the pressure switch which needs to fit either in the pipework, or in the drier if it is possible.

 

It's always recommended that you replace the drier when the A/C system is emptied and exposed to air.

 

I've kept a spare supply of climatronic motors just in case I have problems with those. Both systems I tried to fit had faulty recirculation motors as a plastic arm had split where it went around the gear inside. A bit of superglue soon sorts it out.

 

The only issue with the system that I've had seems to be that the temp calibration seems off - it's a little too warm, even at 18 degrees. I think you can adjust the flap positions with Vagcom though.

[eugopnosaj 0]

Ok cool looking on ebay at MK3 and MK4 pumps/compressors the MK3 has part number 1HO 820 803 D and the MK4 1J0 820 803A (seen one with the end letter as F and K) and they look identical. Also, rather, naively, where would it mount? I take it since the P/N are virtually the same I shouldn't need an additional bracket? Looking at Vagcat the lower section of both the MK4 4 motion and 'rado VR6 alternator/air con brackets are the same so I am guessing the AC goes underneath the alternator? Also need a double ribbed belt.

 

 

Ok got it with the temp switch, I saw a thread on here regarding the drier and rad where someone made their own mounts for the MK4 and looking on eBay at other 2nd hand ones I know this one vaguely fits, it comes with the drier so I'll replace that as you say further down the line.

 

The only issue with Vagcom and the positions is that unless I can get the full loom, which I doubt I can from this guy, I'd need to find another way of connecting it to the ECU...

Edited October 2, 2013 by eugopnosaj

[tony_ack 0]

TBH the issue I have with the flap positions may be down to my system/control unit specifically.

 

The connection to Vagcom is via the OBD2 port (if you have a OBD2 port...) - it's a single wire from one of the pins on the clima loom, which you can splice into the existing signal wire connecting to the port. If you're making your own loom, the connection to the OBD port is going to be one of the easier ones to do!

 

Correct part no for the MK3/Corrado/Passat VR6 compressor is 357820803R - I thik there is a difference between 4 and 6 cylinder on the MK3/Corrado, but I don't know what it is. Have no idea about the MK4 as there are loads of different part nos.

[eugopnosaj 0]

I've been doing a bit of research regarding the part numbers and the first 3 digits denote the vehicle, the 4th is which area (ie 1 is for engine) then the 5th and 6th are a sub area and the last three digits are the item and whether is it left or right. The final letter is for the version. So, with that in mind since the last 3 digits are the same and only the version is different I would imagine that the fixing points will be the same, going on the pictures I have seen anyway (I know assumption is the mother of all f*uck-ups...)

 

The brackets on the 4 and 5/6 cylinders are different and from the looks of it, it won't be very easy to fit the AC to a 4 cylinder vehicle. (for

 

Unfortunately i'm not running OBD2 at the moment so I cannot connect that up, however if I can have the connection I might leave it there.

 

I think I've got stuff to go on now, I will get the MK4 compressor as i am happy with the part numbers

 

MK4 5/6 cylinder

 

MK3/Corrado