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Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53985
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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Marty. I disconnected the positive cable from my battery. I

Customer Question

Hi Marty. I disconnected the positive cable from my battery. I closed the trunk. Neither my fob or trunk release button work. My blade key that I can slide out of my fob works in drivers door but not in trunk. I tried connecting battery booster to terminal in front of fuse box, lights came on but trunk release still won't work. I connected battery pack to alternator, same thing. How Cani open my trunk? It's a99 c230 Kompressor 4 dr sedan. Can I fold rear seats down? Is there a pass way through rear arm rest?
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

Hi, after you connect the booster to the alternator try starting the car and see if the trunk will release with the switch in the car. You could also try locking and unlocking the car with the remote after you connect the booster then see if the switch works. There is no easy access through the back seat.

Let me know how you make out.

Customer: replied 1 year ago.
The car has an infrared key. It will not even turn in the ignition even with booster pack attached to alternator. Is attaching booster to starter any different? Lights come on when booster is attached to alternator, but door locks will not lock or unlock using either fob or console button. Could this be because battery is disconnected thereby not completing a circuit? Could I apply power directly to the fuse which controls trunk lock?
Expert:  Marty replied 1 year ago.

When you put the jumper on the alternator it is the same as connecting the battery. The car should start with the jumper on the alternator. When you power the car from the small terminal under the hood you should be able to lock and unlock the car with the remote then use the trunk switch. The trunk won't open if the car is in anti theft mode. That's why you need to lock and unlock the car or start the car. If the key won't turn with the booster attached to the alternator either you do not have a good connection or the key is faulty. You should check all of the fuses to see if any have blown.

Customer: replied 1 year ago.
Still won't open. I got interior lights, headlights, tail lights. The blade key turned left in drivers door and power window rolled down. Locks will not open or close, trunk will not pop. I'm calling a row trunk.
Expert:  Marty replied 1 year ago.

Good luck with it. If you can start the car using the jump box on the alternator or at the starter you should be able to pop the trunk. Assuming that the central locking worked before all this happen this should just be a matter of disabling the anti theft system with the remote or by starting the car.

Customer: replied 1 year ago.
Nothing worked. I had to cut a hole through the trunk behind the license plate so I could access the cable. Once I connected the battery everything worked fine. Now I just have to patch the hole I made. I don't want to rate you poorly because you were polite and tried your best, ***** ***** still couldn't fix the issue... Don't really want to pay $55 either seeing as your advice didn't work.
Expert:  Marty replied 1 year ago.

No problem at all. I will send your question to customer service for a refund.