1996 jetta starting problems

:crying: I have a 1996 jetta manual transmission. I was installing my amplifier and speakers and two of the wires crossed and blew the 50 amp fuse inline and this started the rest of my problems. The car will not always start when I turn on the key. It tries to turn over but will not. If I play with it or gun the gas sometimes it will start. Also my car stereo will not play when I have the car running. It has power to open the face but not supplying the power to run the lights on the stereo or play music. If the key is in the accessory position the stereo and all the instrumentation works fine. Recently I have replaced the starter, battery, and ignition coil for another problem. No other blown fuses found. Is there a relay that could be causing these problems or am I not looking in the right place at all.

When you blew the fuse, I'd say you fried a couple wires as well. Trace your wiring starting from your ignition switch and try to find some burnt insulation.