How do you fix power Left door lock 1997 Mercury Grand Marquis LS?

Answer 1

You start by figuring out what's wrong with it. That's called diagnosis. Your possibilities here are power supply, bad actuator, or bad latch mechanism (or a combination of multiple reasons). So, you start with the simple stuff.. you check the fuse which supplies power to the relay. If the fuse if good, then you check the relay itself and ensure there's power going to the relay. If there isn't, then you trace the wiring and find the fault.

Then, you have to take out the switch and ensure there's power to that. If there is, then you take off the door trim, reconnect the switch, disconnect the actuator, and ensure there's power to the actuator. If there isn't, then the fault is in the wiring between the switch and the actuator. If there is, then it's the actuator itself.

But if the actuator works? You'll see multiple rods connected to the door latch. Ensure they're connected. Ensure that they move and operate freely, especially if the actuator does turn out to be bad, but in either case, you check that stuff - you have the door trim removed already, after all.

If you're not sure how to go about the steps I listed, I recommend you buy a Chilton or Haynes manual. You can get them at any parts store, or even rent them from the library. They're especially good if you're not accustomed to doing your own mechanical work.