SL500 starting issue

[kvz2000]

Hi All , I have an intermittent starting issue with new newly acquired 2002 SL500 , only when I try to start it for the first time do I get all the dash lights but no crank when I try to start , both batteries fully charged , no clicks from solenoid , interior light does not dim to show power going somewhere , i’ve tried moving auto selector , moving key etc but no joy , after about a dozen attempts it will burst into life and will start without any problem for the rest of the day ? I have also renewed batteries in key fob . Car has been meticulously maintained by previous owner for over 5 years and he has never had this happen . Before taking it to Mercedes garage I was wondering if it could be starter relay ? Which would at least eliminate if it didn’t cure the problem . Question is what relay is the starter relay and does anyone think it could cause this , it seems to be a fairly common fault with not only SL’s but Google search has failed to point me in right direction so far . I really don’t think it’s a starter problem as I would think I would hear it trying to turn and it would surely happen through out the day .
thanks in advance for any help . Just had the car two weeks but really love it .It replaced my 1973 W114 so big change

 

[kvz2000]

Further to above , I’ve noticed I can move auto gear selector from P to D when the car is switched off ? I don’t think I should be able to do this and does this point to a faulty selector , can’t remember the name of the small plastic part that breaks . I’m thinking the car thinks it’s not in park so won’t allow engine to crank