For the past 10 months, this beautiful car has driven the Mercedes dealer and a body shop nuts over an intermittent blowing air pump fuse after some minor body work and a new air pump installation . Not very long after the initial repair, this fuse would blow and turn on the check engine light. He first returned to the body shop that did the work and they referred him to the Mercedes dealer. The dealer spent some time on it finding nothing and sent him on his way. After multiple visits back and many fuse replacements he brought it to us. Our team did a very comprehensive circuit inspection and found two issues. The first was a fuse box, the one in the right corner of the engine compartment, had some suspect water damage and excessive corrosion within the terminal runs. This we believe was causing some resistance issues obviously unrelated to the blowing fuse which was a little baffling. The cause of the blowing fuse was from the air pump itself, we found that while running an air pump test and lightly taping on the case the pump would stop and draw excessive current on our tester, enough to blow a 40 amp fuse. Once we removed the air pump, we found the case of the pump had a broken out piece. The broken piece was hidden in an area under the large mounting bracket. You could see, what looked like external damage, which was caused from something striking the pump. We disassembled the blower housing and spun the fan, you could tell there was play in the motor bearings and you could feel a spot where it could jam up. We will never know where the damage came from but we do know this is the problem that has been making everyone crazy.
This is the type of work we are known best for, complicated electrical diagnosis and repair. We are fortunate to have a team of people that have spent most of their careers fine tuning the skills to make this happen. If you are having problems like this with your vehicle, please send it our way, we look forward to helping you.