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Marty
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53153
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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My 2005 c230 wont turn over.It has good 12 volts.

Customer Question

my 2005 c230 wont turn over.It has good 12 volts.
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

Hi, fuse 52 in the driver's side fuse box under the hood is for the starter motor. I'd start by checking that fuse to see if it has blown.

Expert:  Marty replied 1 year ago.

If the fuse is blown it indicates a bad starter. If the fuse is good you need to test the fuse for 12V when the key is turned to the start position.

Expert:  Marty replied 1 year ago.

If you have 12V to the fuse and the starter doesn't turn the motor the starter is probably bad or there is a fault between the fuse and the starter. If you don't have 12V to the fuse there is a fault with the start authorization circuit which consists of the gearshift, transmission control unit, engine control module, ignition switch and front SAM. You will need to get the car connected to a Mercedes diagnostic tester to check the actual values of those items.

Expert:  Marty replied 1 year ago.

Let me know if you have any questions.

Marty

Customer: replied 1 year ago.
no power to fuse.
Customer: replied 1 year ago.
could it be a relay?
Expert:  Marty replied 1 year ago.

This is where it gets complicated. There are a lot of things that affect the signal to the starter fuse. You really need to get the car connected to the Mercedes tester to view the actual values of the shifter, transmission, ignition switch and the terminal 50 signal to the starter. The starter relay is right next to fuse 52 at position S in the fuse and relay box. You can swap out the relay but if that doesn't help you will need to get the car connected to the Mercedes Star Diagnosis tester to troubleshoot the starter circuit. A faulty park contact in the shifter or in the transmission or a faulty transmission control module or ignition switch or SAM are some of the possibilities.

Let me know if you need anything else.

Marty

Customer: replied 1 year ago.
this happened after i ran over a piece of lumber. I drove it home fine, but after i went to start it it wouldn't turn over. I wonder if theres a reset somewhere?
Expert:  Marty replied 1 year ago.

There is no reset but you might have damaged the transmission linkage. I'd have the linkage inspected to see if it got bent or came loose. If the transmission is not fully in park it would cause the problem.

Customer: replied 1 year ago.
The car is in park wont move and i also tried nuetral. Nothing looks vent or cut.
Expert:  Marty replied 1 year ago.

Will the car roll in neutral?

Expert:  Marty replied 1 year ago.

Hi, I'm just following up with you on this question. Do you need anymore help with this?

Marty