Glen1972

hi I have a 2003 sl500 it was starting fine up until recently, car was parked for few months, I noticed electrical consumer battery was dead so I removed it as per directions . I tried to charge it was no good so I replaced ,by procedure. now the starter just clicks when I turn key, so I removed front battery has per procedure charged and tested and it load test fine and shows fully charged ,installed as per procedure still starter only clicks when I turn key,i then put a booster pack on starter battery and car swings over but wont start. I check for fuel pressure at shrader valve and there is none, listen for fuel pump but cant here it start when I turn key,checked all fuses related to fuel pump and all good, checked codes and only relevant codes coming up are P2314 and B1829 I cant find any service info on either, I should also mention I checked component fuse for starter battery located under the subwoofer on pass side floor and its fine. I cant help but wonder if I have a bad ground and that's why starter is only clicking and fuel pump not running or is it possible I just have 2 different problems that occurred exact same time. also the car has always been starting fine till it was left for few months and only thing I have done is replace electrical consumers battery in trunk and I did so by following the battery disconnect and reconnect procedure everytime even when I removed starter battery. any help is greatly appreciated thanks

Glen1972

update, battery terminals on starter were dirty,cleaned them up and swings fine now, tested got power to fuel pump but its not running when you turn key on so I guess its gone, also no pressure at rail. guess I will try new fuel pump.