MK3 Aircon into MK2 anyone got a guide?

Topic: MK3 Aircon into MK2 anyone got a guide? (Read 7408 times) previous topic - next topic

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #75 – May 25, 2022, 03:59:14 PM

So there are a few things I've learnt doing this.
DON'T DO IT 😅
Pneumatic fitting suppliers only seem to supply steel fittings whereas VW uses Ali pipework so some thought is needed as to what any new piping/fittings can/can't be used. Also some of the VW ends aren't available (MK3 compressor)
Rubjonny used a MK4 HVAC which means less chopping of the bulkhead.
Aside from both pipes to the compressor none of the other pipes fit directly to a RHD shell (the expansion tank gets in the way). The hose from the compressor to the evaporator will need undoing at the mid joint and the half going to the evaporator replacing.
Having said that I'm now going to make some more progress to complete this.
Would really appreciate some help with the wiring. I've stripped what I think is required from the MK3 loom.

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #76 – May 25, 2022, 04:51:31 PM

Quote from: AndyBa on May 25, 2022, 03:59:14 PM

So there are a few things I've learnt doing this.
DON'T DO IT 😅

Literally the first job I'm going to do when I've finished the red one!!

As for the wiring, I've been thinking about this.
My plan is to pull a +12v from the ac fuse in the fuse box, run it through the AC switch on the dash, out to the high and low pressure switch, then into the compressor clutch connector. Then just run a ground to the other connector on the clutch.

I did consider getting a couple of relays and hook them up to the high and low pressure switches, that would be safer for the switches and allow me to fault find easier. Might still be the way forward actually.

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #77 – June 10, 2022, 08:30:01 AM

Quote from: Monkey on May 25, 2022, 08:37:20 AM

Ohh dear, if you've had the compressor on and clutch engaged, chances are that might had damaged the compressor.

I had a mk4 where the previous owner had just cut the pipes as he didn't care about the ac.
I had to replace the whole shooting match.

Oops. I thought that the clutch would be set to engage the compressor if it was powered. I guess all the internal pistons will be well worn now.

I did a test fit of the new fittings and found the dryer to Condenser thread pitch is different to the others so they have changed that. Carlton are based in Rotherham which is an inconvenient 20 mile round trip for me to collect it.

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #78 – June 15, 2022, 10:46:10 PM

Here's what the Burgaclip fittings look like when they are crimped, its a shame the "cage" is blue, much better if it was red to match the car

I suspect I could remove most of it since I think its purpose is to help align the hose clamps when fitting - We'll see!

I've also got a replacement secondhand compressor from Leo Burley. I've spun the pulley which seems to rotate freely without the clutch engaged so could the other one have been faulty? Hopefully this is a "good-un".

Hopefully this weekend I'll get some time to trial fit the fittings and hoses but I've succumbed to that tempting Eibach/Bilstien suspension kit on ebay just before its latest price hike. The rear is fitted, just need to do the front. However I think it's going to revert to the annoying "nose-slightly-up" stance :/

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #79 – June 20, 2022, 12:11:05 PM

I’m looking to cut out the recess myself this week. Did you stick with the MK2 main heater body and modify the MK3 aircon side to fit or fit the complete MK3 heater box?

Cheers

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #80 – June 21, 2022, 06:57:50 PM

You need to keep the central heater/diverted box. This will mate to the MK3/4 HVAC which is MASSIVE compared to the MK2.
As noted earlier, Rubjonny on Club GTI fitted a MK4 HVAC. Which doesn't need such drastic surgery!
Page 2 - 7th Sept update

I'm sure Jon posted a pic somewhere....

Just found a YouTube vid on bending MK4 ali aircon pipes. That would have been handy to have seen a year ago ☺

Bending Ali aircon pipes

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #81 – June 22, 2022, 08:44:00 PM

Appreciate that, thank you

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #82 – June 25, 2022, 09:47:30 PM

So a bit of "fettling" today.
Fitted the old dryer to trial fit the hoses. Unfortunately I could probably do with different connectors but I think I can work with what I've got.
There is some circular mount in the front of the driver's wing that limits how you can mount the dryer. I originally drilled my holes in the inner wing but then found that the dryer electrical connection was up against the inner wheel arch liner so I had to twist it round a bit more. I've attached some "P Clips" along the bulkhead using some M5 ultra thin headed bolts. This allows the scuttle cover to fit properly. I used a bit of hose pipe to gauge the length of hose required for the dryer to condensor.

Unfortunately the "crimping" of Burgaclip connectors are a different thickness to the VW ali pipes. I'm unsure if my "modded" evaporator clamp is good enough for the job of sealing the hoses, seems OK but I've noted that the "connector" can be taken off so I guess I could have it machined if not.

I might take a day off this week to get the hoses crimped so its all connected-up except for the compressor. I'll replace the one in situ when I have some working wiring in-place.

More Aircon pics...

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #83 – June 27, 2022, 07:10:12 AM

I can see why you're telling people not to do it now!

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #84 – June 27, 2022, 02:42:03 PM

There was a genuine mk2 air con set up listed for sale the other day….. in need of restoring but sounded like a lot less hassle. I’ll make do with my sunroof on hot days.

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #85 – June 27, 2022, 08:25:04 PM

Hi Tim, yes I saw that on FB. There is also a LHD one on there too. Be interesting to know if it sells for £700.
My experience just highlights when you mix and match different parts there will be challenges 😅.
But that is part of the F.U.N.

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #86 – June 30, 2022, 09:22:20 PM

Earlier this week I dropped in on an engineering shop in Sheffield to see if they could sort the misaligned "HVAC connector clamp". They rang me yesterday to say it was ready. They needed to make the cut-out for the large flange bigger (the flange is a slightly bigger diameter than the one on the MK3 original).

Today I finished the cutting of the Burgaclip hoses and took the hoses and fittings to Carlton to crimp the joints. Unfortunately they weren't able to do all the 3 because they had run out of the "cages", the "Main Burgaclip man" is on holiday this week so I need to go back to get that sorted

I'll have to go back anyway because I've noticed a mis-alignment of the clips...Maybe it's me but I do like things on show to align. Things like door knob screws too ! Grrrrr

More Aircon pics...

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #87 – July 04, 2022, 11:07:11 AM

Can't be long now!

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #88 – July 04, 2022, 07:15:37 PM

Aside from fitting the pipework, replacing the compessor and getting the system gassed it's the wiring that is the stumbling block!

I rang "The Man" at Carlton today and hopefully they should have more "cages" in stock next week. He should also be able to sort the "mis-aligned" join too ☺

Re: MK3 Aircon into MK2 anyone got a guide?

Reply #89 – August 21, 2022, 08:41:35 PM

The final hoses connected up, need to get it pressure tested now. Unfortunately the guy at Carlton couldn't re-crimp the hose so it is still mis-aligned, arh, onwards and upwards.

I didn't realise when I offered-up my "O" rings at the national meet for the record breaking head gasket replacement I'd handed over one I needed so that meant another visit to City Bearings and Seals, but no big deal.

The 90deg joint next to the battery is a bit tight and the use of a tie-wrap to secure the x-over pipes isn't ideal but I can work on those.

Now to the wiring. rubjonny has shared the MK3 wiring diagram. I can't match any of the wire colours to the ones I've stripped out...Hehe !