A few times my 1983 C30 has not started. It's a dead key, no idiot light and buzzer when I turn the key to start it. The four times it happened I pulled the battery terminals and cleaned them although they weren't actually bad and then it started. This time it didn't work after doing the same thing six times. I knew the battery was old so I bought a new one that I need anyway and new terminals and it didn't work. I'm assuming something with the ignition but I'm kinda stumped. Thanks.