Hi there!

I need a little help with my car. the aircon is not working the way it should.

The problem is: Starting the engine with the aircon turned on, the pipe leading
away from the compressor gets cold quite fast but just for a few seconds. Then
there is a clicking sound (relais i guess) and the pipe gets warm. While
driving with revs about 2500 and speed around 50 km/h the air reaching the
passenger compartment is as cold as it should be with aircon turned on. When
stopping at a light for more then a minute or so: there is the "Click" and the
air comming in gets warmer and ..uh.. humidity rises fast as well.. and the
smell...bah..
Driving again and all gets back to normal function.

What i checked and did until now:

- The passenger compartment filter is new, been in for two months.
- The r134 level is checked and 750 grams of it are where they are supposed to
 be.
- System has no leaks
- Yesterday i found a resistor which had been blown (notice: fuses are all ok)
 the resistor is next to the cooling fan and a mec told me that the resistor
 is needed for switching the fan from level one to level to. Weird thing about
 how that thing died: one of the two cables was melted(!) as well as a part of
 the plastic housing. The insulation of the cable has nice little bubbles at a
 length of ca. 5 cm. That heat didn?t come from anywhere else but the
 resistor.

- I was given the hint to change the dryer/filter(?) of the aircon (aluminium
 housing, two high pressure connections) to make sure the system runs all
 right.

It might help. Damn expensive part though.(about 100 euros)

- one of the little valves at the tubes near the compressor was leaky, throwing
 out a few small bubbles
 (normal tire valve) and was changed. Maybe that was an inication that
 something was choked and the pressure inside the system is too high.

I really hope someone can help me or give me a few hints which other parts i
could check and how.

Thanks in advance,

Ralf