AIR CON. problems.

[MGB]

HI...CAN ANYONE SUGGEST WHAT IS HAPPENING TO MY AIR CON ON MY c200 CLASSIC AUTO 1999. IT HAS SUDDENLY STARTED TO MAKE A LOUD CLICKING NOISE AROUND THE LOWER DASH AREA ON THE PASSENGER SIDE AND THE BLOWER BEGAN TO SURGE. THE ECONOMY LIGHT HAS BEEN FLASHING AND SWITCHING OFF RECENTLY BUT THAT HAS STEADIED ITSELF AND NOW APPEARS OK. WHEN THE AIR CON IS OFF THE BLOWER WORKS OK BUT IS A BIT MORE NOISEY OF LATE. THE AIR CON SEEMS TO WORK OK AND BLOWS NICE AND COLD. THERE IS A HIGH PITCHED SQUEAL WHICH IS EVIDENT WHEN THE AIR CON IS ON OR OFF. ALSO THE ENGINE IS A LITTLE LESS SMOOTH ON TICKOVER WHEN THE AIR CON IS ACTING UP. I CHANGED THE POLLEN FILTER ABOUT A MONTH AGO. THE CAR HAS NEVER HAD THE AIR CON LOOKED AT IN THE PAST......MANY THANKS FOR ANY REPLIES.

 

[television]

I would think that its motor bearings on the fan making the squeal and or something stuck in the fan like paper or a leaf.

There another thread running right now on how to fix, not quite the same car as yours but near enough.

Malcolm

 

[Templar Al]

Hi MGB,

It sounds like you have a pressure drop in the system, causing a pressure sensor switch to dither between on and off. The clicking noise you can hear is probably a relay.

If it is less noticeable in warmer weather, it's probably becausae the gas has expanded slightly, increasing the pressure.

One other possibility - is the battery up to scratch? I have seen a number of threads on here where strange electrical system behaviour has been cured by replacing the battery!

Regards,
Alan.

 

[jberks]

When you say the blower is surging - it it suddenly going faster than the switch setting?
The only thing I am aware of that can do this is the fan regulator. It's solid state, but can certainly whistle exactly like a fan bearing so it's not always easy to differentiate. It is located in the passenger footwell just under then fan. I also haven't heard it click - just whistle.
Why it should behave differently with and without aircon I'm not sure but as it is cooled by the airflow, temp may have an effect.
This does not explain the aircon cutting in and out though, unless the aircon is sensing a problem and shutting down, or you have low gas too.

 

[MGB]

Update

Thanks for replies....I decided that rather than get a mobile air con expert out to my house I would book the car in to a local garage (Formby, M/side), to get the system checked over and re-gassed etc. The cost was £75 and I was very pleased with the service. The refridgerant was down to 400 from the max of 850. The system was pressure checked and sound tested. A coloured dye was also added to pinpoint any leaks and I need to return next week for a further check (free of charge)...Everything seems ok at the moment....Regards Mike.

 

[MGB]

Blower Switch

I get one problem sorted and then notice another!!!!!!! I can hear and see the blower above the passenger footwell is working even with the switch on 0. All the other levels work fine but surely the thing should not rotate when the switch is set to 0 !!! Any thoughts about this problem...Many thanks in advance.