1986 300E Electrical Gremlins
 

I know it is a slim chance but there might be an easy answer to this – or at least some good ‘first places to look’ but I gotta start somewhere.

Car is 1986 300E W124 M103 with 224k miles.

I have begun to have phantom lock and unlock of the doors. Sometimes I have to lock all three (door, door and trunk) locks several times to get the car to lock. All the locks work but it unlocks right after I lock it. Sometimes I return to the car and find it unlocked. Sometimes it locks all by itself while driving down the road. Sometimes only the door I open with the key opens, the rest stay locked, sometimes for hours of driving, then they all unlock when I go to lock the car. (The doors all lock normally but immediately unlock)

Additional symptoms:
Fan cuts out intermittently (sometimes maybe under throttle). Sometimes I can make it go on by operating the window buttons. If I hold the window button in ‘up’ the fan goes on – off when I release, sometimes I have to hold two window buttons down to get this effect. Sometimes but not always the radio cuts out too – but the presets are not erased. Sometimes the wiper operates at ‘double time’ – intermittent and normal are at fast speed and position III is super fast – like 4x instead of 2x – but only when the car is in intermittent no fan mode.

Thanks for any help, David

You need to inspect the TRUNK lock. It can spring unlocked and unlock the whole car.