Hi. I have a 97 audi a4 1.8t. The car will not crank. When the key is turned, there is no sound (not even the clicking from the starter solenoid that you get when the battery is dying). There was no change from: jumping the vehicle, changing the ignition switch, checking fuses and relays for obvious burning/corrosion, changing starter, checking neutral safety switch, checking and changing central lock module, and cleaning battery terminals+main engine ground. Thus far, the only way the car will start is by jumping the s-terminal on the starter directly from the battery. Starts every time, very easily! I should also add that sometimes after jumping it, it will start normally 20 times in a row! After 5 min, back to the same problem. So, what exactly is my issue?