My 1985 380SL was in storage all winter like it has been each year since I bought it about 5 years ago. This month I put the battery back in and tried to turn it over. Everything seemed to be in order, but the starter would not spin the engine. I replaced the starter and also bought a bought a Noco jumper pack. I have also tried conventional jumper cables. I don’t know what to try next. Any ideas?