Blown Tach and Aux Fan fuse
I have an 85 190E 16V with the exact same problem. I started leaking coolant from a small crack in the thermostat just above the distributor cap(the leak would only start when the car was running for 10 minutes and pressure built up). The leak would drip onto the distributor cap and blow my aux fan and tach. I replaced the thermostat cover which stopped the leaking coolant from dripping on the distributor cap but even after this fix, I am still blowing my fan and tach fuse. I have also started blowing another fuse but haven't bothered to check which one yet.
Question I have for you is: Did you fix your problem and if so how? Any advice would be greatly appreciated.