Hello all,
Sorry I have not updated this thread, but things have moved on!
The fault diagnosis on the aircon is as follows:
Broken wiore in the 3 pin plug to the compressor. This was not allowing the compressor speed sensor to give the "OK" and allow the compressor to run. Cycling the ignition got the compressor to run briefly, but it would then shut down. Wire fixed, compressor now runs. Sadly, now the system is running under pressure it has showed up another fault.
The condensor is shot. There are less holes in Rab C Nesbitts vest.
The HP port valve leaks. Bubbles are evident when you take the cap off.
I also believe the duo valve to be faulty as if you have the temp dials set to the blue dot, cool air abounds. Move the temp dial and the heating only blows hot.....Full hot.
The supplying dealer is refusing to pay for the repairs to the condensor saying the system was working when they sold the car to me. Lies! I arrived to collect the car only to be greeted with "the aircon is not working and our specialist reckons it needs a thermo switch. Get it repaired at a non MB specialist and we'll pay the bill provded you phone us for authorisation".
Quite why they did not get thier specailist to repair it, I am not sure. But now it wants nearly £800 spending to repair it, and the dealer is not haiving any of it. This is the last mail I got from them, my mail is at the bottom of thiers IYSWIM:
"Mr & Mrs Darling
Further to your emails of Friday 22nd June I would confirm the following:
On receipt of an invoice from Go Cool we will pay for the inspection and
subsequent repair of the broken wire - £45.00 (+VAT?). This was as agreed on
collection of the car.
I have spoken to our air conditioning specialists and they have confirmed
the system was NOT leaking when regassed, apparently the system was 40% full
before regassing. Therefore we will not be contributing towards the
condenser and associated parts and labour as the system was deemed
satisfactory and working, other than the wiring fault discovered on the
morning of collection.
We will pay on receipt of an invoice for the replacement serpentine belt.
With regards to the duo valve I would propose making a claim under the
warranty supplied with the vehicle.
Regards
*
-----Original Message-----
From: Jim Darling [mailto:*]
Sent: 22 June 2007 17:11
To: sales@*
Subject: Summation of what is what!
Hi chaps,
Last email for today before I leave for the day.
I realise that the last mail I sent out had loads of parts prices but no
explanation of what was found to be the problem, or how it was diagnosed. The following is what I have understood to be the issues, and the required steps to fix.
Very nice and competent chap from Go Cool came out to see the car. This is
what we, and he found out.
A broken wire in the connector to the speed sensor on the compressor.
Repaired it on the spot so the compressor now runs. Excellent. Previously,
when the ignition was switched off the sasfety circuit reset. Next time the
car was started and the a/c selected, the compressor clutch would engage,
then disengage as the speed sensor got no "OK" signal from the compressor
and assumed the compressor has seized. The safety circuit then engages to
prevent the seized compressor from snapping the serpentine drive belt. As
soon as the broken wire was diagnosed (George is a vehicle electronics
engineer as well), and fixed, the compressor clutch can be engaged and stays
engaged. The ignition cycle was what was being simulated by popping the fuse in and out of the circuit.
Gas was analysed as R134a and was free of air. Good news.
Condensor is leaking, Bad news. I'm not sure why this was not picked up by
the guys who gassed the car up? Surely it would have been part of the basic
tests they would have done as they even went to the trouble of stickering
the car to say it had been re-gassed. When Go Cool shone his UV light on the
condensor, it glowed green in lots of areas and was clearly only leaking
under high pressure now the compressor was running. Maybe that is why the
leaks were not picked up.
Filter drier requires replacement as part of replacing the condensor. Bad
news. These have to be replaced as a pair or the repair will not be
warranted.
HP port is leaking, bad news. George tried to reseat the valve in the port
but it was beyone repair. Fortuantely the cap on the paort has an O ring so
seals quite well, but this is not a long term fix!
He also noticed the serpentine belt is WELL past its best with cracking on
the flat side, and worse the ribbed side has chunks missing and is cracked.
Can this be replaced ASAP please? If the belt lets go, and it looks likely,
the car will lose engine cooling, a/c, PAS and so on...
Even though the compressor now runs, the car still only blows hot from the
drivers vent. We clamped off the output hose from the heater matrix to
prevent the heater from receiving hot water as if the temp dials were set to
cold, and the vents all blew cold down to between 5.8 and 11 deg C.
Excellent.
So it seems the duo-valve is broken..... This is the valve that controls the
flow of coolant to the driver and passenger sides and is controlled via the
thumb wheels on the control head. As air distribution seems to be OK, I am
guessing the head is OK, but we will not know until the other issues are
fixed.
All the best,
Jim"
