Help Car not cranking W220 S500L

[Dblock]

Apologies for posting when I need something but could really do with some help. My dads W220 S500 had an airmatic failure at the front, both sides were to the floor. After reading around online the first thing we tried was to replace the airmatic relay(upgrading the Seimans to Hella). That didn't help. My dad started to check all the fuses pulling each one in and out. Now the car won't start.

I have checked the fuse diagram and all the fuses are back in their right places. The car has power, when you turn through key positions 1 and 2 its okay but when you turn to start the car it does nothing.

So far we have checked all the fuses bar the extra ones in the boot and under passenger front seat as these don't seem to be related. We have checked the rear passenger fuses in the footwell and they were okay besides the one for soft closing doors which is now replaced and working.

Searching online people say it could be the neutral safety switch and try starting it in neutral. After banging the gearshifter down hard managed to get it into neutral but nothing. Tried rocking the car back and forth just incase the starter was stuck but to no avail. I have ordered a new starter relay as its not clicking(the green one) will try this tomorrow but am not holding out.

Seems some people with similar problems have linked it to EIS, SAM's(not sure what they are?), water damage, K40 relay amongst others and alot of threads don't seem to tell how they got their problem fixed.

The car has been fantastic, done 185,000 miles and was still going strong. I would like to fix it myself, handing it into a garage is obviously a good idea but with the car not being valued much anymore , once the electrical and airmatic faults are fixed it could be over £1k.

Any advice would be great and if anyone has a star system nearby please let me know.

 

[nadeem]

Dude no need to bang the shifter down you may have caused further damage. Just switch on ignition to 2, press brake pedal then the gearshift lock is released for you to shift in N.

While you were investigating its possible the battery has drained below the threshold to start the car. Quick possible fix, charge the battery for few hours then restart car...

 

[Dblock]

Hi Nadeem,
Thanks for the reply, the shifter would not budge in either ignition position and with my foot on the brake. I noticed you have a w220, can the shifter definately move when the cars not started. From all the posts I looked at when people call Mercedes Assistance thats what they do. I understand though that it could do damage. You would think it would have a shift lock, even my mums w203 has one.

I forgot to mention I checked the battery with a multimeter and it was reading 11.7v which is low but was still working before. I installed another that I was going to put in my car which made no difference(bosch silver S5 85ah), trickle charged the original battery to 12.8v and still nothing. What a big battery though! 100ah, the biggest I have seen.

 

[nadeem]

Hmm checked mine when in position 2 lock is released when i press the brake pedal. Its possible brake light switch issue hence why its not releasing the shifter. Check if brake lights activate when pressed.. Ideally you need a diagnostic machine to check for codes. I use poor mans carsoft tool. Check the fuse for brake light i believe its in the right fuse box when looking at the engine.