HI bought a Mercedes E320. 1999 model. When I bought it the battery was flat, so they jump start it and I drove it for 40 km and I get the battery tested. They fitted a new battery and I drove it for five days, The horn didn't work so I replaced it's fuse. Left the car on for a while to check the back window (on right side) which also was'nt working. Remove the top plastic cover from the engine. I wiped en cleaned the cover with a cloth and put it back on the engine. When I want to start the car, it doesn't read the key. I took the key to be tested and they said nothing is wrong with the key, but still doesn't respond to the key. Please, I need some help!.