Since I'm not familiar with the harness your using, the easiest way to check your stinger, is to connect a couple of jumper wires directly from the closest battery to the small terminals at the base of the stinger. Polarity should not matter. Before you connect the jumpers, turn your key off, disconnect the wires from the top two large terminals, then put your meter on the lowest Ohms setting. On the Ohm setting, read across the two large top terminals. Depending on the type of meter you have, there should be no reading or no movement of the meters needle. After you hook up the jumpers, read across the top terminals again. If your stinger is working, you should get a reading of zero or 1 or 2 ohms. If that happens, the stinger is working and your problem is not the stinger.