Please check connection according under instruction:
Remove all the leads from harness except to connect the yellow color lead from radio harness with Battery wire (Constant power wire) from car harness, red color lead with ACC (Accessory power wire) from car harness and black color lead with ground correct.
Then try to turn on the unit.
In addition, detect the ACC wire connection on your car.
1. When you car turns on, is the ACC wire having a 12V voltage power?
2. Is the ACC wire works intermittently by bad contact with the red color lead from the radio harness?
The red color lead from radio harness is the trigger wire. When you connect the yellow lead and black lead from radio harness with the Constant wire (12 V battery wire) and Ground wire from car harness, the radio can not be powered on. Once the red color lead detecting the 12 V voltage from ACC wrie from car harness(the voltage of ACC wire is zero when the car turns off), the radio can be powered on automatically.