Aurel1

Hi there, i just got a 2012 c63 with that was hydrolocked and managed to get away with new injectors, spark plugs and starter. Flushed the oil and changed filter (it had fuel in it). Car started and i let it run for about 15 mins. Did a second oil and filter change then the car wouldnt start. Cranks but doesnt start. The only fault code was left MAF sensor short circuit to the ground. I though that couldn’t be the issue for the car not to start. After checking a few more things found Fuse #23 ( Fuel pump 20A ) blown, replaced fuse blew instantly ( ignition completely off ). Fuel pump is not turning on at all. Removed the fuel pump module relay and tried another fuse. That one blew aswell. The ground to earth is good. Battery is fine aswell. I dont know where to start tomorrow. Any advice ? Thanks

NZ-Merc

One trick I use with repeat blown fuse is install a 55W headlight bulb across the fuse terminals with some jump wires, when there is a grounding/short to earth issue the bulb shines bride, when there is good/no earth issue the filament shines very dull. The bulb takes the load so wires are not damaged by heat.

The light bulb can be installed going while I wiggle looms unplug things to isolate the problem.
Not sure what your auto electrical abilities are, you need to be able to work a multi meter and start checking for short to earth problem.

Just interesting weather it is related to any recent maintenance.

All the best,
Dave

Aurel1

Thanks for the advice Dave. I will go and have it checked today and see how it goes.Also i have a friend that works at MB so he will be helping me out aswell with fuses , diagrams and the fault codes that its showing. I saw on the forum that someone else has had the same problem but he hasn’t posted for a while or replied there. Hopefully its nothing major. I will update this afternoon.

Aurel1

Found the issue today. The computer started bringing up the left side MAF sensor, crankshaft and camshaft. Started testing each one until it stopped blowing the fuse. The mechanic that dealt with the car before left a cable of the solenoid under the rocker cover and it got pinched. Took that out, insulated it and the car started straight away. Just have to do the air filters now and the rocker cover gasket because its leaking oil into the exhaust. Thanks