Do I understand that you can turn the lift gate lock cylinder both ways for "unlock" and "lock"? On my old stuff I can only turn it clockwise to pop the latch. The wire you want is a 20 gauge white / red in the left connector. It needs to be momentarily grounded, but it's not that simple. There are two resistors inside the missing switch. The Body Computer sends a voltage out on that wire, and that voltage will change depending on the value of the resistor that is switched into the circuit. Typically they will send 12 volts out there, but it could also be 5 volts. It's irrelevant to the story but if we use 12 volts for the description, there are four possible conditions. Full 12 volts will be seen on that wire most of the time. If you ground it, there will be 0 volts. When you turn the switch to "lock", one resistor will be switched in and there may be 8 volts on that wire. In the "unlock" position a different resistor is switched in and there might be 4 volts seen on that wire. The 4 and 8 volts are interpreted by the Body Computer as the "arm" and "disarm" signals. There's a 99 percent chance grounding that wire would not cause any damage but most likely that will not initialize the anti-theft system either. You need to ground one end of a resistor, then momentarily touch that white / red wire to the other end of that resistor. The problem is they don't say what the values of the resistors are. There is a separate diagnostic manual for the anti-theft system that would have those values listed in the switch testing section. Is there any chance you still have the old lift gate? If you do you could read the resistor values with an ohm meter, then you would know the value of the resistor to use. From my limited experience with cruise control circuits, 560 ohms, 2200 ohms, (2.2k), 10,000 ohms, (10k), and 18k are typical values. That's how the computer can tell the difference between four different switches when only one wire goes to the switch assembly.
Mar 21, 2011 at 9:27 PM
