Non-working electric door locks!

[John Mc]

I like to have everything work on my newly acquired ’77 Town Coupe. My door locks would not operate so I went to work. I have all the wiring diagrams and I’m ready to pull my hair out. After working probably 9 hours yesterday on removing both door panels and testing the left side actuator, (the right side is missing) I STILL do not have locks. I have power, black/white stripe at both switches. Also, I’ve tested the switches for power out and they are fine.
Before I put the right side door panel back together, I tested the locks probably 50 times from both the drivers switch and the passenger switch and the left side actuator was working to perfection! I then put everything back together and ……no locks!!!


Dan, after searching the archives, I found something you wrote about a similar problem back in 2011. I’m trying to decide where to go from here. Any help is appreciated.

“The door locks use a ladder-circuit. Both switches must be 100% working for the locks to work.

When you push lock on the driver's switch, power goes up one side of the circuit, through the passenger switch, to the motor, back through the other half of the passenger switch, then back to ground through the drivers switch.

When you push lock on the passenger switch, power goes immediately to the motor from that switch (bypassing one half of the driver switch), back through the other half of the passenger switch, then back to ground through the drivers switch.

GROUND is always completed at the driver's switch. Verify you have a ground connection there and that the driver's switch is fully functional.

The power windows work the same way. Each window is like a single door lock.”

[John Mc]

I HAVE LOCKS!

Turns out, one of the ground connections was corroded. I opened it up, sprayed contact cleaner and blew it out with compressed air. After reassembly, the locks are working with perfection. So the moral of the story is to open and check the contact points. This Lincoln sat in a building untouched for 25 years.

[TonyC]

Simple solution to a complex problem; good! I suggest applying dielectric grease to that ground connection, to reduce the risk of corrosion in the near future.

---Tony

[Dan Szwarc]

Congrats, John!

[John Mc]

Congrats, John!

Thanks Dan, the satisfaction I get out of accomplishing items on this car makes me get out of bed in the morning! It’s really coming along now.

Fixed: headlights, wiper switch, decklid lock, AM-FM 8track, dashboard decals, door locks, ashtray lights, new tires, polished rims, trim pieces replaced, cornering lights, wiper blades, muffler, plugs, wires, distributor, boiled and lined fuel tank.

To do: Heaadliner, brake system, etc.

Before and after: