A/C help pleeeeze!

[M-R-P]

Ok, after having my A/C serviced a while ago, I'm still having intermittent failures. If it starts at all (sometimes you don't even hear the compressor engage), it runs fine for a few minutes and stops. The pump is only 18 months old and a genuine Volvo one, fitted at the local stealers.
What I'm thinking is this...
Ever since I did my door trims, I've had weird readings on my outside temp readout. it starts at --.--C and gradually falls to about -42C. I'm aware there's a temp sensor on the bottom of each door mirror. I guess this is why the A/C won't work, but I'm not sure.

I've disconnected all the plugs in the door looms, cleaned and reconnected but nothing changed.

Is there another sensor, elsewhere that could be causing the problem?

I really need the A/C working, it's bloody hot here at the moment lol.

Thanks in advance...

[V70 Graham]

I'm sure A/C systems have a mind of their own, the VAG had a similar problem, would work fine then not at all, left it alone for a while and now it works all the time !

Cars eh.....

ps Don't worry micro heatwave wont last

[M-R-P]

Hurrumph, want my A/C working.

Been reading some guff on VOC about the temp sensor in the driver's door going squiffy. Might have a tinker with it later.
Anybody know how to get the glass out without using a hammer?

[Harvey]

Have a look at the plug on the door to the body loom are the pins clean and dry ,try a contact cleaner spray,also look at the wires in the rubber boots going to the door aswell that they aren't damaged corroded
Is the sensor clean on the control panel at the temp controls little grill in the middle of panel in the dash.

[M-R-P]

Plod/poverty spec mate - no grille in the dash control unit however, the door plug and adjacent wiring are things I haven't thought to look at.

Cheerz Harvey

[oblark]

You could just wind the windows down and listen to the engine singing

[stephenevans99]

It does sound like it's related to the external temp sensor, although there is also a temp sensor on the evaporator housing - stops the pump if if reads the temperature on the evaporator is too low to prevent ice forming.

[M-R-P]

It does sound like it's related to the external temp sensor, although there is also a temp sensor on the evaporator housing - stops the pump if if reads the temperature on the evaporator is too low to prevent ice forming.

Where's that then Steve? I've been faffing about in the engine bay for ages now, might have clouted it without realising.

Although my money's on the outside air temp sensor as that would also stop the A/C working (I think)

[Harvey]

Just a couple of bits of info outside temp sensor at 0 c it's 6318 ohms at 20c it's 2424 ohms at 25c it's 1941 ohms at 30c it's 1513 ohms. So you can test sensor with test meter.
Ac sensor cut in at 6.5 c and cut out at 5.5 c
You have a linear sensor on the dryer ,drivers side of the condenser a/c rad in engine bay plugs in at the top of the can.
The evaporator the rad in the dash has a sensor fitted to it.
There is also a thermo switch on the compressor.
This is from Volvo pocket data book.

[M-R-P]

Result!
First, thank you all for your contributions. reading all your ideas inspired me to stop being an old woman and get at the bloody thing.
Driver's doorcard off, unplug, wiggle and reconnect everything... nowt.
bashing the door switchpack... nowt.
checked the connections in the green plug for the door mirror... clean as.
Decided to trace the wires for the sensor, one white and one grey. got to the green plug and found three other white wires.
I looked down the hole in the plug where the wire I suspected would connect... clean.
I looked down another connection for a white wire and hey presto - fluffy white stuff!
Looked at the corrisponding pin in the switchpack - also furry.
after ten minutes of scraping and prodding i plugged everything back and turned the key... success!
temp gauge and A/C all working


Happy MRP

[Harvey]

You can now sit down and cool down then go inside for a well deserved beer,well done.

[V70 Graham]

Well done mate, get little MRP to pat you on the back !

[M-R-P]

gonna collect some brownie points later...

[stephenevans99]

Well Done Mr P.

....as Harvey says - the evap temp sensor plugs into the plastic housing where the evaporator lives behind the dash.....probably a pig to get to, so luckily it's not that at fault !!!!

[JamesT5]

If the car thinks it's below 0c outside then the A/C won't work, so if you have a faulty sensor it may think it's below ) even when it's not and so shut the A/C off.

Regards

James

[M-R-P]

If the car thinks it's below 0c outside then the A/C won't work, so if you have a faulty sensor it may think it's below ) even when it's not and so shut the A/C off.

Regards

James

yeah, that was my suspicion - it couldn't be just a coincidence.

[stribo]

Well done mate, though as the car belongs to your wife, I'd have got her to do it. hilarious:

[M-R-P]

Well done mate, though as the car belongs to your wife, I'd have got her to do it.

If only.
She can't even get the top off the power steering tank lol.
Hows Relfski getting on with the VVT issue on her R? pmsl

[stribo]

If only.
She can't even get the top off the power steering tank lol.
Hows Relfski getting on with the VVT issue on her R? pmsl

She's ordering the gasket for the solenoid, I think that's going to be the extent of her involvement.

[y2blade]

Well done mate