'87 Mondial US version. What works: If both doors are closed, and I push down on the passenger side lock plunger, both doors lock. When I pull up on the pass side plunger, both sides unlock. If both doors are closed, and I lock the door on the pass side using the outside key, both doors lock. Both also unlock with the key. So, as long as I am using the pass side exterior key, or pulling up or down on the plunger, the system works properly. What doesn't work: If I push down on the driver's door plunger, the passenger's door plunger does nothing, and the driver's door plunger cycles back up. If I try to lock using the passenger OR driver's side switch, the passengers side does nothing, the driver's side cycles down then back up again. When I try to unlock using the switches, the pass side does nothing, the driver's side cycles up and down. When I try to lock using the switches, neither side does nothing. What I've done: Taken both switches out and cleaned them with contact cleaner. Nothing. Taken the panels off and inspected, nothing looks broken our out of place. Cleaned the wiring connections. Cleaned and lubricated the linkages, etc. No difference. Any thoughts?
Fixed it. After thinking about my symptoms, I figured out that one thing that was never happening under any of the scenarios was the pass side electric lock was never activating or running. I disconnected the wiring on that side, and sure enough, that caused the system to work on the driver's side. So the issue was narrowed down to something in the pass side motor. It was never running, and it was causing the driver's side to not work properly, too. The wiring was all cleaned up, so it must be something in the motor. A quick "Italian tuneup" on it (a few taps with a hammer on the motor) and all is working now.
