w124 only starts in neutral during cool weather
 

Well, it's dropped below 60 in Louisiana.

I knew when my car would only start in neutral.

My guess it's the NSS. It just seems odd that it won't start in park when the car has been sitting for awhile and the temp drops below 60.

Started happening last winter.. and I forgot about it until it happened the other day.

Just wondering if it could be something else.

Car: 1994 E320 Cab.

similar experience
 

I had a similar experience with my W124 - it was the NSS, mine has a different kind of NSS as its a different model of transmission but the fault was similar.

I would suggest you inspect the wiring too at the end. if its a bit crusty with blue stuff then its a good idea to solder new wires on, the wiring is easy to remove - it terminates a few inches below the ignition switch in a 4 pin square plug. Remove the knee panel to find it, its fished through a hole near the gas pedal/steering column.

To test - you can use the 3 pin test port near the brake cylinder, with transmission in P or N, key turned you should see a good 12V at the purple wire. Test with a high wattage lamp to verify enough amps are flowing to actually pull the starter solenoid coil.

Perhaps you might also check the extent to which the shifter connecting rod bushings have worn. If the bushings at both ends of the rod have worn too much, that may collectively be enough loss of movement to prevent the shifter from being able to place the shifting lever on the transmission itself into a position where the neutral safety switch is fully in the Park position. The NSS and the shifter position function that enables the key release are separate and the successful operation of one does not defivitey mean the proper operation of the other. The difference in starting temperature could be a manifestation of the connecting rod bushings shrinking and expanding just enough to make a difference.

Now pointing to shifter bushings.

I can wiggle the shifter just slightly in park and it starts.

My guess is the cooler weather just shrinks the bushing enough to cause play.