Prince Somorin

I noticed that there is no air coming out of the rear AC vent in the center console. I only have the front controls which by the way is finicky as it doesn't always change temperature even though I rotate the dials.

I'll appreciate any guidance.

Thanks.

2009 GL450

Plutoe

Very simple you have issues with your AC system------find an indy who knows the MB system and have your issues defined

Miguk_Saram

Check your Owners Manual, page 214. In the center of the right control dial you should have a button that reads "REAR off" this toggles the air flow for the rear passengers.

Changing the temperature setting on the dials does NOT change the temperature of the air coming out of the vents. As with all A/C systems, the vent temperature will remain constant based on the refrigerant (r134a) charge in the system (and whether you recycle the cabin air, or pull air from outside). Low refrigerant = poor cooling and humidity removal. The dials control the 'desired' cabin temperature, and signal when to lower the blower speed.

If you feel that the air from the vents is not cold enough, then you may just need to recharge your a/c. This is a simple DIY: Purchase a can of refrigerant from your local Walmart or auto supply store and follow the instructions. Be sure to get one with a hose to connect to your high pressure side (if you dont have one already), as opposed to just the refill can.

R-134a Car Refrigerant Kit, 20 oz

Prince Somorin

Thank you for a detailed response. I appreciate you.

Air started coming from the rear vents this morning but the temp control still moves occasionally on it’s own.

Prince Somorin

The AC control is back to working perfectly. I swapped battery so perhaps it was going through some sort of learning process.