Morning All, new fish here. Tremendous resource this site, wish I'd thought to look for it 5 years ago! I've a gremlin with an intermittent twist that might just cause heart failure if I cant get some quality advice...hence my joining the forum. I have an 02 plate C270 estate which has developed a bit of a teaser! Drove the lad to the station the other day and the dash display including speedo, computer, indicators etc went completely blank. Engine unaffected and radio still worked. Obviously electrical I figured (and my ignorance of sophisticated car electronics is almost complete). By the time I arrived home some 15 minutes later, its back. Next time I come to take the car out, can't turn the ignition key in the barrel of the ignition. Central locking works but the key simply wont turn. next day, it works again!! I take it to my local (non Mercedes) village mechanic, a good bloke but without the sophisticated diagnostic tools of a main Mercedes dealer. He does have some diagnostic setup and no codes are evident, but then it's working at this time anyway. I get it home, it breaks again. Over the following 2 days it breaks, it works, it breaks, it works. Classic intermittent fault. I'm told it's either the key electronics or the EIS electronics and even in a main Merc dealer with appropriate diagnostics, they cant tell which. Thus usual method of elimination is to try your spare key, if that works, bingo, it's the primary key at fault. However, if you dropped your key into the sea while wading at chest height bass fishing, it often doesn't work any more!! (Right about now you may be regretting me joining the forum). Bottom line, this car is on it's last legs but I need to keep it running for the rest of this year without spending best part of a grand on ignition bugs. My assumption, with little car knowledge but a healthy dose of logic is as follows: It's most likely the EIS because otherwise why would the dash have gone dark on me? A faulty key can't cause that can it? What I don't want to do is order a new EIS only to fund I've spent 3-£500 on a "mindless parts swap" and still have the pleasure of the fault. Whats niggling me is some geezer in the trade mentioned that it's likely to be the EIS but it's not 100% sure. Is it possible to get to be 100% sure without selling a kidney to find out (ie a Merc main dealer)? Your help is appreciated. PS the reason I'm being as tight as a mermaids brassier is that my business has just failed after spending 2 years nursing my wife back to health from cancer whilst simultaneously doing the same with my young son who has a rare bone disease and has had 15 operations to try and repair his leg at the Royal national Orthopaedic Hospital in Stanmore (which is miles from where I live by the way). It hasn't been a joyful 2 years! But if I can fix this sodding car I'll be happy man!