I purchased a turbo timer w/ a harness & was just wondering if the break (brown) & speed sensor (purple) cables need to be connected as well or can I just connect the seperate harness that I bought?

 

They dont have to be connected, its not necessarly. Just use the harness and plug everything up. When you turn on the turbo timer, youll have to go to the settings. One of emm lets the turbo timer (a)add time when you drive it hard (detected by the RPM wire), and another one has it set to (b)what ever time you want it to be set to (mines at 1 minute). Make sure you have the timer set to (b). If you have it set to (a), then youll notice that the time will slowly increase by itself, if you go for long drives itll go up to 15 minutes. Have it set to (b) and you should be fine