2003 V70 T5 No A/C in hot weather due to low speed,

lh123gt · Post by **lh123gt** » 07 May 2014, 14:15

My A/C works fine until the weather gets over 85 F and I get in to traffic and the engine idle, the A/C compressor stops. I have noticed that the cooling fan run very slow at idle but speed up as soon as I rew the engine to approx. 2000 rpm, at that time I can use the A/C again.
The high pressure switch at the drier has been replaced and A/C recharge to specification.
PLEASE HELP

Post by **jimmy57** » 07 May 2014, 14:28

Sounds like a fan issue. The a/c high pressure sensor read by ECM will shut off compressor if pressure goes a bit over 400 psi. It will go that high if in the 80s or above with low condenser airflow.

Check at battery cable connection on back of alternator for AC voltage (not DC). Failing alternator could be screwing up operation of th fan control module. The EFCM takes DC and makes AC to operate the brushless cooling fan motor.

Post by **vtl** » 07 May 2014, 17:08

Check both low and high ports pressure in the morning. System may be overcharged.

Post by **abscate** » 09 May 2014, 04:20

Does the 2003 suffer from the same compressor shim problem the P80 cars have?

Post by **vtl** » 09 May 2014, 10:39

lh123gt · Post by **lh123gt** » 10 May 2014, 20:50

jimmy57 wrote:Sounds like a fan issue. The a/c high pressure sensor read by ECM will shut off compressor if pressure goes a bit over 400 psi. It will go that high if in the 80s or above with low condenser airflow.
Check at battery cable connection on back of alternator for AC voltage (not DC). Failing alternator could be screwing up operation of th fan control module. The EFCM takes DC and makes AC to operate the brushless cooling fan motor.

Thanks for info. Today was hot enough to repeat the problem; I run the car until hot and then let it idle until the A/C shut off due to low airflow over the condenser ( the fan never speed up ) I turned off the A/C and the fan stopped. After a few minutes I turned the A/C on again and the A/C compressor started and the fan went to high for about 10 second and then slowed down to low speed, and stayed there until A/C shut down again.
The alternator is charging 14.25 volt cool and 13.75 hot
What in the world is going on ??

Post by **abscate** » 12 May 2014, 03:51

Check the gap, on the AC clutch, between the face of the clutch and the plate. I believe ( to be confirmed) the gap should be in the range 0.3-0.5mm

It's common on these cars that the gap opens with time and the clutch magnet no longer holds the clutch in when hot. The symptom is the AC starts out working fine for about 10 minutes then cuts out with the clutch releasing at the compressor.

You can either disassemble the clutch and reshim it (no need to open up AC system or recharge) or shim it with bread clips or other thin plastic.

lh123gt · Post by **lh123gt** » 12 May 2014, 08:53

I just checked my clutch gap and it is 0.85 mm !! I have 145000 mile the car. Should I replace or reshim the clutch at this time? what's your take? I found a 10 mm screw head in the center of the clutch, is that the only fastener holding the clutch?
Thank You very much for your help,
Leif

Post by **jimmy57** » 12 May 2014, 09:33

Remove the thick shim.
No need to do anything else if it is cooling well.
Remove that bolt and then use a couple of screwdrivers to pry out the clutch plate. Unless your TX car has lived up north in salt land it will pry off very easily with no damage to clutch plate. If it doesn't move when you insert screwdrivers and begin to pry then stop and do not get at all forceful. I have never used my puller on a compressor on P2s I work from here.
There could be one or two washers inside the hub that slides onto compressor splined shaft once you get plate off. A shim can be stuck to end of compressor shaft many times.
With gap that large you likely can leave both out if it has two with the typical .40 mm plus .15 mm shim washer stack.

lh123gt · Post by **lh123gt** » 18 May 2014, 08:53

So, Yesterday I removed the front cap to gain some access to the clutch plate, (I have worked in roomier places), anyhow, the 10 mm bolt came out without any protests, but the plate decided to hang on for dear life, very carefully I increased the pressure evenly until the plate gave up, just a minute before me. Inside I found two Washers, one 0.20 mm and one 0.80 mm, I made up a new washer from shim material 0.20 mm thick to add to the 0.20 mm washer and left the 0.80 mm washer out.
The clutch gap is now 0.40 mm, and finally the A/C works fine even in hot weather and the radiator fan goes to high speed when needed. I will never know how much a Volvo dealer would have charge me to fix this problem. Thank you very much Jimmy57 for your great insight and will to help.