Short Circuit in the Wiring Harness
This cable is for the SRC/FX3 shock absorber control system. It runs from the switch down under the left side of the tunnel to the left storage compartment where it connects to the controller. The SRC had an error 41. This is defined as a short circuit on the switch sensing voltage wire. In the past someone had removed the carpeted panel that covers the left side of the tunnel. When the panel was reinstalled, a connector from another cable was allowed to lie on top of the SRC switch cable. After the panel was installed the seat crushed the connector on top of the SRC cable and pressed the cable against the metal rear tunnel panel with a huge force. The crushing pressure caused the wire insulation to cold flow and then the wire made an electrical connection to the chassis.
The short was identified by disconnecting the cable at the SRC controller and at the switch. A resistance measurement was made from chassis ground to each of the wires in the cable. Each wire should read infinite resistance because the cable was disconnected on both ends. One wire measured 2 ohms to the chassis.
This is a left door lighting cable on a '91. The problem was no incandescent instrument panel lighting for the buttons and switches. The dimmer module was found as open circuit. After repairing the dimmer module the left door handle light was noticed as inoperative. The lamp tested good. Then the broken wire was located. The lamp dimmer module was destroyed when the broken wire shorted to ground at some point. Also note how the white door courtesy lamp was crushed but not enough to cause a problem. Judging from other witness marks in the door, the cable was damaged when someone adjusted the window glass upper stop bracket.