thats what i had to do to get my pioneer to work...works great now. i hid the switch so if i get pulled over i can hit the switch and show the officer it DOES work like its supposed to....(but only when johnny law is behind me!)h2omelon said:On a Jensen you will need a toggle switch. Connect one side of the switch to grond and the other side to the parking brake wire on the Jensen. You have to switch the switch on and off a few times ending in the on position.