jimenezstm

Everytime I turn the key all lights go on, ac works etc it only makes a tick noise but doesn't start, this problem start after we disconnect the battery pls help me.

Maj. Dundee

Then it has to be a bad connection at the battery between the cables and the posts.

yourbenztech

Check battery connection first if connections are good try to spray some corrosion cleaner and make sure all cables are clear and clean! if all is good and still not working it may be a weak battery, check voltage on your battery or try to charge it for 45 minutes at 12v.
If battery is good and connections are good you need to move to diagnosis number 3...please advise me so we can continue...

CLLARK1

Check if when key is in the start position if the tach jumps to the right.If it does the computer believes the engine has started and disrupts current to the starter.There is a Mercedes bulletin addressing this problem.Date: August 18, 2008Order No.: S-B-15.30/68 Starting System - Tip Start Cycle Ends Prior to Start-Up.It states
If you receive customer reports in the above model vehicles of the tip start cycle ending prior to the engine starting, this may be due to the tachometer momentarily jumping above 2000 rpm causing the starting procedure to be aborted before the engine starts. To resolve, perform the below steps.
1. Remove starter per WIS instructions below. 2. Lightly coat teeth of starter ring gear with paste, A000 989 76 51. Note: Only use the paste specified. Do not apply too much paste as it can cause interference with the signal picked up by position sensor L5. 3. Reinstall starter .The grease is very expensive and difficult to find.I spoke to my local MB service manager and was told I could use never seize.It worked great and I no longer have the problem.