Why is my gas meter not reading gas level in my mercedez Benz c230 compressor

USA are you or Europe???? hint cars not the same.world wide.
Mercedes-Benz ( the makers here have no service manuals sold to owners) <<< makes repairs hard and expensive.
R12 OR IS CAR UPGRADED TO R134A OR R1234?

well it has 2 caps on the port. so 2 there are
there are 2 lines there, one is huge one is small
one side is called low side, and the the other is high side.
best is not touch the 300PSI (21 BAR.) SMALL LINE TUBE.
do not attach a walmart R12 can here or it will explode. in the face, OK end safety rant1, and where goggles.
the low side is about 10X LESS ABOUT 30 PSI
THE R12 RETURNS HOT AND IN GAS FORM. USING LARGE TUBE.
THE COMPRESSOR COMPRESSES THE GAS BACK TO A LIQUID STATED, AND SEND THIS LIQUID TO THE CAB EXPANSION VALVE TO GET COLD.

ONLY MESS WITH THE LARGE LINE , PORT
R12, IS FACTORY PORT,

THIS IS ORIGINAL 1999, WHAT IS THERE NOW I'VE NEVER A CLUE BLINDED IN A TEXT BOX. HERE.. MESS ONLY WITH LOW SIDE. OR BOOM,
THE HIGH SIDE CAN EVEN HIT AND EYE AND BLIND YOU.
EASY. GOOGLE ARE NECESSARY.

IN REAL SHOP THESE 2 ARE CONNECTED TO A TOOL CALLED A MANIFOLD. AND IS USED IN A SAFE MANOR.
A SKILL TECH TRIES NOT TO INTRODUCE AIR TO THE LOOP
AND DOES SO PURGING LINES IN THE MANIFOLD FIRST.
AIR IS BAD, BAD NEWS. (AND AIR IS EVERY WHERE)<LOL

Try www.benzworld.org/forums for a merc answer

may need to replace the pressure switch for the ac as well they will go defective a lot of times as well.cheap part go to auto zone or advace parts or any you choose and ask for a ac cycle switch and they will hook you up.

no
have the ac system checked by an ac specialist shop as the freon is checked by pressure gauges

Does it open the trunk? Does the panic button work? More than likely, the batteries are too low and should be replaced.

In your A/C control you have two rotary switches, if you set it at blue side it mean you select it for a/c if you select it for white or read it will blow hot and switch off a/c compressor this the basic, in your car have climate control a/c system it will select need to switch on a/c compressor or not by your settings and temp sensors reading , is this information helped you?

Most of the time Check engine light will come due to Gas and gas cap issues. If you ran out of gas and gas lost pressure it will bring the light on. Make sure to fill take with premium (91 octane) gas and make sure gas cap is closed completely. loose gas cap will cause the engine light to come on. If after doing this you still get the engine light warning, take to authorized mercedez deal for code check.

you will probably need an ignitoon lock cylinder.

The owner manual is the place to find the answer.

try new fuse or buy aftermarket one