850 T5 auto box, ABS, heater and air con-help!

Re: the a/c problem - yes, you do put a dye into the system and use a black light to find leak - but most likely evaporator. You can view one side of it by removing the heater motor resistor and inspecting with black light when dye is in the system. if leak is bad, you may be able to view the dye in the condensation that drips from under the car with the a/c on, but dont forget system needs to be recharged (again!!) to be able to put dye in

If it is the evaporator, it's not as bad to replace as a lot of people say - though if i may say so i think the people who say it have not done the job themselves!!!

If it is the evaporator, change the accumulator as well.

Volvo time is around 7 hours plus parts at approx £450.

You do need to invest in 'special tools' though to remove the a/c pipes - set from snap-on approx £40 - you may only use once but still a big saving!!! unless your local ford dealer will lend you..........(they're the same as R12 and later fords)

I wrote a quick procedure with some photos - as Haynes doesnt cover this job - if you're interested (kevin.loomes@btinternet.com)

And yes, i would imagine your screen misting up inside likely to be heater matrix - which you can change when you do the evap!!!!

Do it yourself!!

I really appreciate all the advice-this is the first time I've ever used these sort of Forums and it's great that people are so helpful!

Based on my research, advice etc. so far I've ordered a new PNP switch and heater matrix so guess what I'm doing at the weekend! Judging by the Haynes manual the replacement of the matrix seems v. straightforward and doesn't involve removal of much of the dash, just the panels under the fascia on each side. I'm just a bit worried by the comments about doing the matrix and evaporator at the same time-this suggests that perhaps the matrix removal etc. is more involved?

Looks like a trip to the dealer to have the fault codes read on the ABS before I buy a new ECU. Is it possible to get a code reader for the OBD II socket-if they're not expensive I would guess it would be a useful tool to have? I'll have the AC re gassed and see what happens!

I'll keep you posted as to how successful I am at the weekend!

Nick

[Chris_Rogers]

Nick,

As you seem to be from Kent I may be able to help further to read codes etc. I'm on the South Kent coast close to you so e-mail me directly if you're interested.

Chris

A brief update!

Did the heater matrix yesterday-fairly easy to do, took me about 3 hours but I did a coolant change as well. Problem of misting up solved!

PNP switch next!


Nick.

[roy chu1]

Hi Nick,

I need to replace my heater matrix. Is your car working fine now. because I also have a demist problem.

If it a home problem then I might be able to do this.

Also do you think the heater matrix would be the same on the v70 t5 as compared to the 850 t5.

Would like to know

Many thanks Roy

Roy,

Yes, the car seems fine now-no more misting up and no more burning smell from the centre vents!

It was relatively easy to do, a bit fiddly-I just followed the procedure detailed in the Haynes manual. I don't know whether the V70 is the same or not.

The manual tells you to clamp the coolant hoses at the bulkhead (engine side) but I drained the radiator and block as I wanted to put in new anti-freeze anyway.

A couple of words or caution-when you release the matrix housing from the coolant pipes there is a lot of spillage inside the car so have plenty of rags etc. laid in the footwells! Also all the screws are Torx type, various sizes so make sure you have a good range!

Cheers,

Nick

Greetings,

Interesting comment about the ABS ECU affecting the speedo and cruise control...

I've had the ABS light coming on intermittantly while driving for a while - diagnosed by local garage as the right rear sensor (according to the code they read). Sensor was replaced - didn't fix it, and they now say the ABS ECU probably needs replacing (cost about £600 total).

Very recently whilst driving at high speed (motorway) I've occasionaly had the cruise control and *most* of the dash instruments die on me - speedo, rev counter, petrol gauge, temp gauge, trip computer (except central LCD clock), milometer, trip meter - only the turbo boost gauge was unaffected. The instruments all die (go down to zero) and then come back to life - this repeats every second or so. No warning lights come on at this time and everything else (engine, A/C, lights etc) all seem fine.

So given that the ABS ECU affects the cruise control and speedo, does it also affect the other instruments listed above ?

I've had suggestions that the cause might be a weak battery (since checked and eliminated) or a worn ignition switch - any thoughts ?

Regards.

Nick Pitfield.

A quick update.

Have now replaced PNP switch and ABS ECU and bulb. Everything now works fine. Both jobs fairly easy to do-my local Volve dealer lent me the alignment tool for the PNP switch! Bay 13 instructions are excellent for the PNP replacement. Also flushed the tranny fluid while I was at it. Gearchanges noticeably smoother.