I noticed on one of your previous post for an '89 -190 2.8.
that you mentioned the wires were disconnected and jumpered to the switch on the a/c dryer/reciever.
Is this the same car ?
If it is , it is possible the a/c service person has now fixed this wiring when he recharged the unit. Have you checked that?

Also, if this was done by a previous owner, the car may have been running hot and this was an attemp to help that out.