Originally Posted by red_2005_convertible

Hi 180,
I think you're almost there. You've shown that your switch is good. I'm assuming you have the connector off of the switch at the moment. Here are some other suggestions. I think they go the same direction as Pizzaguy was pointing but might be easier to perform. To show you have a good ground, measurement the resistance from the connector pin 4 to chassis ground (any metal part, like the bolts holding down the SLA). It should read less than 1 ohm (probably much less, but that depends on how good your meter is). If that's good, your wire from pin 4 is good, and you have a good ground. It looks like you measured the voltage at pin 49 of the BCM. To check the wire going from BCM pin 49 to the door lock switch pin 8, measure the voltage from the connector pin 8 to either the connector pin 4, or your chassis ground. This should read 12V. If that's good, then the wire between the BCM and the switch is good. If both those measurement are good, you could jumper connector pins 8 and 4 to see if the door locks close. (Sometimes things look good at the low voltages and currents the DMM uses, but at higher currents things fail.) Does your fob open and close the doors? Measure the voltage at BCM pin 78 while opening and closing the doors with the fob. That measurement should give the same results as opening and closing using the switch. With the above set of measurements, I think you'll of isolated the issue to either the BCM or the CLP, assuming all of the wiring checks out. I've had some issues with 2 of my CLP's in the past where the pins on the board that mate to the harness connector corroded away (probably water that I didn't notice until the clp failed). Fortunately, there are extra unused pins on the CLP board, so I was able to move them over and get the CLP working. I've also replaced the vacuum pump motor on one of them.
Good Luck, sincerely
Jerry