Constant Speed ​​Solenoid does not work in forward

[Peter]

The Constant Speed ​​Solenoid on my 280SL (1969) works fine in reverse, but not in forward. It doesn't do anything then.

The oil pressure switch might be broken, but could it be something else? Could it be Is the 3-way solenoid adjustment? Or are there other suggestions?

[Lori]

Simple way to test the pressure switch.  Swap the switches on each side of the transmission.  If the switch is bad, it will now be an issue with reverse and fine in drive.

[wwheeler]

If swapping doesn't work, It could also be the wire that crosses over the transmission that connects the two switches. One side is drive and the other is reverse. I forget which side is which.

You can also disconnect the wires on each switch and then see if there is continuity when in drive and reverse. You need a helper for this. The switches ground when switched.