Hey guys new to the forum just recently bought a 94 golf. All i have done so far is replace the O2 sensor. The car was running fine before i changed it but was experiencing some bad emissions so replaced it. Once i replaced the O2 the car has started fine since then, but just all of a sudden it wont start. When i turn the key I can hear relays and clicking, but it wont turn over. I had to push-start it to get it home. Any ideas? Thanks for the help!

 

Check the connection on the batt terminals, make sure they are clean.
check connection to the starter selonoind and the possitive connection from selonoid to the starter motor.
If evrything is good , try the hammer approatch.