Heater: 70: - Front Windscreen Demister

C70 GT · Oct 26th, 2009, 11:05

Hi all,

I am having problems with my front windscreen demister and I am hoping you can help!

Basically in the eearly morning and evenings, the front windscreen mists up like crazy and I cannot see out of the windscreen. I have tried using the demister control but it seems to be having no effect.

The air con is working fine and so is the heater.

Forgive me if a similar post has been made somewhere before but I did a quick search and could not find any results.

The car is a 1999 C70 GT.

Many thanks in advance for any help.

John_C · Oct 26th, 2009, 12:19

First thing I'd check is are you getting air onto the windscreen when you put it in the demist setting. Also worth cleaning the inside of your windscreen if you've not done it for a while.

If you are getting air to the screen and it's clean then when was the last time the pollen filter was changed as that might be blocked/waterlogged. Finally are you losing any coolant as a leaking heater matrix could also cause this.

Sprintman · Oct 26th, 2009, 12:35

Heater matrix could have a small 'weep'. I had the same problem but wasn't noticably losing any coolant, changed heater matrix, problem fixed!

gandalfwhitewizard · Nov 24th, 2009, 16:55

I have a similar problem having only recently bought a v70 t5 last week...and what fun its been!
Where do I start drove it all the way from Huntingdon to Kent no problems no funny noises, no lights etc.
Next day I drove to work and back home and noticed that the pass. side started to mist slightly although A/C seemed to work and clear it. Checked the water and noticed it had dropped slightly so topped it up and then read all the problems associated with heater matrix etc. Checked the footwell and seemed o.k.
Day 2 - Alarm wouldn't turn off from remote and became possessed! AA came out because I also got a nice Engine Management Light on after driving for sometime and just as i got home the EML came on.... heater problem still the same.
Faults not found by AA and fuse/battery removed. Fault seemed to be resolved.
Day 3 - Drove to work and home round journey of 80 miles and delayed due to accidents then noticed a fine mist and plenty of steaming across the screen...strange i thought but seemed to go off when a/c on. Engine temp. in the middle all the way home.
When I got home checked again and found the culprit was coming from the heater matrix!
Parked the car and went back to my Cougar...after much searching I have sourced a new matrix and o-ring seals and today tackled the job without removing the dash from instructions posted here. When I checked under the carpet it was saturated and really heavy it has been leaking for ages! Something i couldn't have found on the test drive but something i would say get your head under the dash if your buying one of these!
So i am now awaiting the new part (tomorrow) and put it all back together and change all the anti-freeze.
Think the only consolation was this forum to help point me in the right direction and the fact i've done the job not my garage costing an arm and a leg!
Considering selling it though as it does seem a bucket load of trouble as i havent even got to the bottom of the EML. If anyone has some thoughts on that one. I did stop and have all the wheels changed around on the car and a new tyre on prior to the light coming on...

Hobblygoblin · Nov 24th, 2009, 19:33

Is the car dry otherwise?

Any damp/wet stuff in the car or boot?

gandalfwhitewizard · Nov 24th, 2009, 20:00

HG,

Yes dry throughout it appears to be just the pass. footwell.

Oct 26th, 2009, 11:05	#1
C70 GT New Member Last Online: Oct 26th, 2009 21:04 Join Date: Feb 2008 Location: London	Front Windscreen Demister Hi all, I am having problems with my front windscreen demister and I am hoping you can help! Basically in the eearly morning and evenings, the front windscreen mists up like crazy and I cannot see out of the windscreen. I have tried using the demister control but it seems to be having no effect. The air con is working fine and so is the heater. Forgive me if a similar post has been made somewhere before but I did a quick search and could not find any results. The car is a 1999 C70 GT. Many thanks in advance for any help.

Oct 26th, 2009, 12:35	#3
Sprintman VOC Member Last Online: Mar 13th, 2023 22:39 Join Date: Jan 2006 Location: East Herts	Heater matrix could have a small 'weep'. I had the same problem but wasn't noticably losing any coolant, changed heater matrix, problem fixed! __________________ VOC Member 19553 '03 V70 R AWD, standard, so far. '96 855 AWD, BSR twin outlet exhaust, Polybush engine steady. HID Dips. '98 V70 AWD. '98 V70 SE. '96 855 2.0 20v - Gone. '82 244 GLT- Gone, but not forgotten. '61 122S - Long gone!!

Nov 24th, 2009, 19:33	#5
Hobblygoblin Member Last Online: Sep 8th, 2011 11:58 Join Date: Nov 2006 Location: Hove	Is the car dry otherwise? Any damp/wet stuff in the car or boot? __________________ 1998 C70 GT T5 Auto Cassis Pearl

Oct 26th, 2009, 12:19	#2
John_C Allons-y! Last Online: Jun 8th, 2020 15:32 Join Date: Dec 2004 Location: Winchester	First thing I'd check is are you getting air onto the windscreen when you put it in the demist setting. Also worth cleaning the inside of your windscreen if you've not done it for a while. If you are getting air to the screen and it's clean then when was the last time the pollen filter was changed as that might be blocked/waterlogged. Finally are you losing any coolant as a leaking heater matrix could also cause this.

Nov 24th, 2009, 16:55	#4
gandalfwhitewizard New Member Last Online: Dec 19th, 2009 22:26 Join Date: Nov 2009 Location: faversham	I have a similar problem having only recently bought a v70 t5 last week...and what fun its been! Where do I start drove it all the way from Huntingdon to Kent no problems no funny noises, no lights etc. Next day I drove to work and back home and noticed that the pass. side started to mist slightly although A/C seemed to work and clear it. Checked the water and noticed it had dropped slightly so topped it up and then read all the problems associated with heater matrix etc. Checked the footwell and seemed o.k. Day 2 - Alarm wouldn't turn off from remote and became possessed! AA came out because I also got a nice Engine Management Light on after driving for sometime and just as i got home the EML came on.... heater problem still the same. Faults not found by AA and fuse/battery removed. Fault seemed to be resolved. Day 3 - Drove to work and home round journey of 80 miles and delayed due to accidents then noticed a fine mist and plenty of steaming across the screen...strange i thought but seemed to go off when a/c on. Engine temp. in the middle all the way home. When I got home checked again and found the culprit was coming from the heater matrix! Parked the car and went back to my Cougar...after much searching I have sourced a new matrix and o-ring seals and today tackled the job without removing the dash from instructions posted here. When I checked under the carpet it was saturated and really heavy it has been leaking for ages! Something i couldn't have found on the test drive but something i would say get your head under the dash if your buying one of these! So i am now awaiting the new part (tomorrow) and put it all back together and change all the anti-freeze. Think the only consolation was this forum to help point me in the right direction and the fact i've done the job not my garage costing an arm and a leg! Considering selling it though as it does seem a bucket load of trouble as i havent even got to the bottom of the EML. If anyone has some thoughts on that one. I did stop and have all the wheels changed around on the car and a new tyre on prior to the light coming on...

Nov 24th, 2009, 20:00	#6
gandalfwhitewizard New Member Last Online: Dec 19th, 2009 22:26 Join Date: Nov 2009 Location: faversham	HG, Yes dry throughout it appears to be just the pass. footwell.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)