Heater matrix

Clarkeez

Active Member
May 27, 2014
60
0
Bedfordshire
Cupra R 2003 AMK

I've been driving 40 miles a day through 2 winters now, and now I just want my heating to work, so I've taken the dash out in attempt to reach the mystery location of the heater matrix.

I've got this far, so far..

MZVUfU5.jpg


The top of the heater box is still inaccessible by the looks of it, but until I get the chance to work on it again next weekend, I'm wondering if any of you have done this before and have any tips?

:confused:
 
Last edited:

BadBoy03

A Mk1 Is For Life, Not Just For Fun
Sep 6, 2016
678
439
Somerset
Is it just the heater gone or the control panel?

My whole climate control packed up a few weeks ago and it turned out to be a badly corroded socket in the front wiring loom. The garage fixed it so i can't say what they did exactly. They did have to sort through the wiring and test for faults. The socket joined two batches of wires together and inside was sodden and corroded. They simply cut the socket out and wired them together. All perfect now.
 

Clarkeez

Active Member
May 27, 2014
60
0
Bedfordshire
Thanks for the reply!

The climate control itself seems to be working properly, no faults in VCDS and we've checked that the servos for the temperature flap actually does move the flap so I don't think it's electrical.

When the car is at full temp the heater is only ever so slightly luke-warm. If I turn the heating fully off, and drive for a few minutes and then put the heating back on, it is slightly warmer for just a moment before returning back to a useless temperature.

I'm hoping that this means the matrix is partially blocked. I hope we've ruled everything else out!

I'll get to it at the weekend and confident we'll be able to replace the matrix with a new one so I will update the thread with the results.

At the moment the thought of a new matrix not fixing the issue is beyond me and I'll most likely buy another LCR just to get heating back LOL
 

BadBoy03

A Mk1 Is For Life, Not Just For Fun
Sep 6, 2016
678
439
Somerset
Hi mate,

I know what you mean about getting desperate just for heat! I only had the heater out for a couple of weeks, just happened to be the coldest few weeks, frost and sh8. I had to drive along with hot water bottles on the dash, just to keep the mist down. I was dressed like a michelin man in my high vis work coat so looked f ing mess inside the car. I do hope you can get to the bottom of your problem. It really is crap having no heat at this time of year! It does sound like you've very little left to try!!
 

Clarkeez

Active Member
May 27, 2014
60
0
Bedfordshire
I've only gone and fixed it! Wohooo! :funk:

It seemed the old matrix either has an internal bypass, or had really bad cholesterol because it took the hose water twice as long to reach it's way through the new matrix.

It was a big job to get out. I wish I had the time to chill and take some pics for future people but I'm just going to do a little brain dump here...

Step 1: Remove entire dashboard, steering wheel and clocks
I done this quite carefully but still only took a few hours. I made a separate bag for the nuts/bolts of each section which helped when putting it back in.

BE CAREFUL OF THE LOOM AND WIRES, ESPECIALLY THE ONE WHICH GOES TO THE LITTLE SENSOR IN THE MIDDLE OF THE WINDSCREEN BLOWER.

Also (1): You need to drop the steering column for later.

Also (2): The clips behind the heater ducts (onto the dashboard) are an absolute pain in the ass and I used strong Velcro instead of reattaching them.

Step 2: Unbolt the heater box from the firewall
Just before: Remove the cabin filter assembly, and remove it from the heater box (under scuttle)

You need to remove the hard boost pipe, then the head shield which is between the rear of the engine / turbo and the actual firewall. There is 2 flaps in the firewall foil directly behind the turbo which has 2x 10mm nuts in them. Be careful not to drop the nuts behind the firewall carpet when they come loose!

On the N/S of the firewall, pull back the carpet around where the hard air-con pipes enter the firewall and you'll find 2x gold 10mm nuts in quite awkward positions.

Once loosened off, you need to dismantle the "junction box" where the air con pipes go in, as that is still holding onto the heater box.

Step 4: Loosen the big support beam under the dashboard
There's 2 13mm bolts on each side, plus a couple torx ones on the top and a few others I can't think of, you'll work it out. This doesn't need to come out, but just need to be loosened so you can pull the heater box out enough to get to the matrix

Step 5: Replace matrix and reverse everything

:D
 

BadBoy03

A Mk1 Is For Life, Not Just For Fun
Sep 6, 2016
678
439
Somerset
Good job mate!

Does sound like it was a pain in the ass, but at least your perseverance paid off! No more cold winters for you...celebrate with a long, toasty drive. [B)]