Broken Wire

My solar system is down.  I changde the battery which cost $95, it did not work.  So I change the solar controller first $30 piece and latest from a different brand for $23.  Still the system is not working.  I remember reading in the Q and A in the internet someone measures the voltage.  So I tried and found that the voltage on the battery terminals is the same as the solar panel.  When I measured the battery, the voltage is much lower.  So finally, I decided to measure the resistance of the wires.  I found one wire open!  I could not believe this.  I keep changing different component of the system which cost a lot of money and I did not check the wires.  Wires are passive and therefore I am caught in a paradigm that it will not fail.  How wrong was I.  Once I change the wires, my system work like a charm:)

I am not good at troubleshooting anymore.  I just pay a lot of money to fix something when it should cost me next to nothing.  Luckily, I did not throw away what I thought was bad components like the battery and the solar controller.