Location would help to guess if the issue is cold / ice.

http://www.peachparts.com/shopforum/general-information/349764-how-deal-ice-locks-washer-wiper-door-trunk-glass.html

http://www.peachparts.com/shopforum/tech-help/158363-door-lock-issues-link-thread.html#post1214456

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__________________
ASE Master Mechanic

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D

https://www.boldegoist.com/