A/C intermittent problem with the air flow

[jruanoru]

Hi all,

I have a SL320 from 1998.

The problem is related with the A/C. Sometimes, the air flow decrease (the power), but I don't touch any button of the console (and it's not on AUTO mode). After a few minutes or seconds, the air flow increases automatically, to the correct flow power... I don't know why is the reason... probably the filter is dirty... I don't know!!!!!

It happens when the car stops or when the car starts to run. It must be due to the movement of the car, when taking a curve or something thus.

The problem is not related with the AUTO button. I put the power of the air flow to the MAX position, but sometimes the flow changes (decrease) for 5 or 10 seconds, between low speed and high speed. It is like something is covering the tube... may be a leaf???????

Could help me somebody?

Thank you very much in advance.
Regards,
Jorge Ruano

[TX76513]

Jorge, next time this happens lightly wiggle you ignition key left/right and see if the fan starts running again. If yes, it may be time to replace the ignition. if no - well at least we ruled this out

[jruanoru]

Hi,

I think the motor is OK, because the fan is working (non stop until I press the button to turn off). Probably are the valves.

Today I've observed that when I press the air re-cycling button, sometimes nothing happens and sometimes the airflow is greater. Do you think that the valves are involved in the air re-cycle circuit? Or, may be the air filter?

I think that the air filter is only for the external air, and when the air re-cyling button is pressed, the air doesn't pass for the air filter... isn't it?

Where are the valves and where are the air filter? Can I clean the valves and/or the air filter? Is it easy to do?

Thank you in advance and regards,
Jorge Ruano

[Mike Miller]

Maybe I am way off base here, but my 92 500 SL changes air flow volume in A/C/Automatic Mode every time I accedlerate hard. I think, hope, , it is normal. Under hard acceleration the system appears to drop the compressor and lower air flow. As soon as I let up to cruise, all operation returns to normal. Under light acceleration, no change occurs.

Lea,
Any comments?

[LeaUK]

Not noticed it myself, but my euro '93 has no auto mode so maybe that's why?!

[jruanoru]

I have more information about the problem:

When I ignite the engine and I turn on the A/C I put the maximum power of the flow (I touch the button for the flow speed to the maximum). The A/C works fine, with the maximum speed of the flow... but after 5 or 10 minutes, the speed of the air flow decreases, I don't touch any button, I don't touch nothing .

The A/C decreases the speed automatically after a few minutes but I don't know the reason. After it, I can't increase the speed of the flow to the maximum power. The display of the flow power marks the maximum power, but It isn't true, because it decreases, but the display marks the maximum power... why????

Thank you in advance.
Regards