I have a 2000 Honda Civic .... In hot weather, right after work, my car won't start. It just makes a click noise by the relay (solenoid?)... I replaced the battery and it worked fine.... Then, a few weeks later, I got the same problem when as soon as I drive and motor is hot and I switch it off and want to start it again, then it just make a click sound by the relay. If I bridge the selonoid then it starts perfect... I replaced the ignition and the selonoid but still have the same problem. Please help me solve this problem.
If making a bridge across the solenoid always works, then you either need a new starter relay or you have a bad connection in one of the following places -
Small connector on the starter solenoid
Connections to the fuse in the starter circuit
Connections to the starter relay (on the switched side, not the coil)
It is also possible there is a bad connection to the battery