1998 saturn 4 cyl. when the engine is cool it starts fine. but after running for a short time and turn it off i cannot start it right away. i have to wait for 20 minutes or so. the starter solenoid will not engage until after the engine has cooled down. when its warm and i try starting it there is no click sound from the solenoid. no dimming of headlights and so on. what does normal operating temp have to do with the solenoid not making contact. and what needs to happen?