1995 c220 door locks

[jdparker]

either door wont unlock or lock w/ key at the door but if i use the trunk lock i can lock and un lock both doors, does this mean both tumblers are in need of cleaning or repair?

i look forward to hearing back from all of you with past experience on this..

thank you.

jack parker
jdparker1966@sbcglobal.net

[bergmjh]

If the key turns then the problem may one of three other problems.
1. Physical connection between the key and the sensor switch is bad.
2. Key Lock/unlock sensor switch does not work.
3. No power or bad wires into the switch.
I have never diagnosed the problem on this style of car but have diagnosed other earlier pump driven lock systems so you might have to adapt what is said her to you're car.
Check the fuses first, then if the fuse is good look up in the procedures how to remove the door handle. When you have the door handle out of the car simulate the movement of the key to the lock/unlock switch and see if the locks work?
Not sure if the lock/unlock switch will be a part of the door handle or a separate switch mounted inside the door? Check the movement of the switch and see if you can get it to move by itself. (Note you may have to simulate a closed door by rotating the door latch assembly to get the lock switch to be able to lock/unlock)
If the locks do not work by manually moving the switch there may be a problem with the electrical part.
How to check the electrical will take lots of explanation so please let me know if the rest of this checks out before going there. Good luck
John