Q: Won't start unless I wiggled the solenoid harness. Extreme break pressing or shifting through gears several times.

There is a ground or broken wire issue in your vehicle causing the engine to not start. Check the harness to the solenoid and see if there is a loose wire or a broken wire. If the wiring is good, then check the wiring to the brake light switch and see if the wires are loose or broken. If the wiring is good, then the shifter interlock solenoid in the shifter is shorting out and needs replaced. Note: The ignition system is good as the engine starts and runs. If you need further assistance with your electrical issues, then seek out a professional, such as one from Your Mechanic, to help you.

Hi there. Based on your inquiry, I can see how you might be confused as to what’s causing your starting issues with the Jeep Grand Cherokee. If the car only cranks over when you wiggle the electrical harness; it’s quite possible that the harness itself needs to be replaced. I would also check your main electrical relay; especially if you’re having problems with accessories. Since there are so many possible issues, it might be a good idea to have a professional mobile mechanic come to your location and complete a car is hard to start inspection.