Multitude of small annoyances
 

Have a 1994 C280 with 77000 miles. The air conditioning has been doing strange things of late. Sometimes when it seems hot in the car the airflow will be so-so. Then out of the blue airflow will increase. Once there was hot air coming out the right dash outlet and cold out of the rest. Can't get air of any kind to come out at our feet.

Periodically the speedometer will stick on zero. Will respond to a finger thump to the instrument cluster glass. My repairman sez there is a bulletin out on this, something about moisture, but on checking he found no moisture at the proposed trouble spot. Also the light behind the clock is out. Is the instrument cluster difficult to get into? Tools necessary? Cost?

Almost forgot. How often do you replace the cabin filter. How does one get to the cabin filter?

I really like this car but the subject header says it all.

The AC system can be searched in the archives. There is a great article by Steve Brotherton under the DIY tab at the top of the page. Steve also describes a method of using the A/C display as a diagnostic tool
http://www.peachparts.com/shopforum/showthread.php?threadid=6650&highlight=climate+control+display

David C Klasse expands on that info at the thread http://www.peachparts.com/shopforum/showthread.php?threadid=13940&highlight=climate

A search for key words (C230, A/C, etc) will reveal other threads. Your symptoms occured on my 98 C230, and the A/C display trick indicated it was the Evaporator sensor http://www.peachparts.com/shopforum/showthread.php?threadid=25026&highlight=champ

The cabin combo filters can be ordered for the best price at Partsshop via the 800 number at the top of the page. I use the Bosch which is both paper and charcoal for removal of dust and odors. The location, instructions, and frequency of replacement are found at the Bosch site http://www.bosch.de/aad/en/produkte/filter/innenraum/a_kohle.htm . Click on the 'vehicle specific information'and then on 'installation locations according to various models' and a list of cars appears. Click on C180-C280 and an acrobat file of instructions for your car appears. They say a change frequency of 30,000 miles, but I do mine every 6-12 months.

Hope this helps.

The cabin filter is on order and have found the instructions to install it. Thanks!

Would like to take the speedometer issue a little further please. How do you get to the needle stop to put something on it?

Also, who might know how to change the light behind the clock.