When on a highway drive lasting more than 1 hour, my heat and A/C system seems to shut down. The blowers won't work and adjusting the temp. has no effect. Must turn off car, let it sit for a while and restart it. The systems then work, at least for a while. My dealer has not been able to find the problem. Diagnostic tests come up clean. This happens in both heating and cooling seasons. My car now in shop for last 7 days and dealer is still stumped. I told them to keep car until they can find, and fix, the problem.
Mercedes-Benz Q&AAsk Your Question
2011 Mercedes-Benz S550 Question: Anyone else had the same problems with heat & A/C &, if so, were they corrected
Answer #1Greg's Orange Auto (15229 Answers) , Orange, CA - (714) 361-9386globalhelper January 07, 2013, 15:52Master
poss blower motor resistor
Replyclewa, July 14, 2013, 07:52Rookie
same problem sat in dealer for 6 weeks and was later told silcate in the system and I would
need to replace several parts to the tune of 8200.00 please advise
2012 Mercedes September 04, 2013, 10:02Rookie
On the S550,2011 and 2012, when it is cold, the heat will not work most of the time unless you put it on "high". The dealer said to take it off of automatic and put it on manual. What in the world? Is this a Mercedes or a Ford? At least on the Ford, the heat works. This has happened on two different year models. The only way you can get any heat is to put the heat on "HI". When you do that, it gets so hot in the vehicle you cannot breathe, and then you have to let it cool off, and start the process again. One of the dealer's solutions was to do as you had to, and turn the car off and restart it. The dealer said he thinks my vehicle is possessed. I took it to him one day, and even though the settings were the same on the driver's side and passenger side, there was heat blowing from one side and AC from the other. I think it is a defect Mercedes is not willing to admit to. Meantime, the rest of us have to suffer with a heating system worse than a junk car.