I have a 1986 New Yorker. My blower motor is stuck on full high anytime the car is on. I am in the process of troubleshooting this and during my research from what I can tell this system is unique to 1986 and 1987 only. I have started this thread because I have found virtually no information online pertaining to how this works electronically, common issues and fixes.


The way I am reading this schematic is there's the head unit. It talks to the vacuum control box and also sends signals to the blower motor controller.

The head unit on this car has two plugs on the back. I have not taken a photo of that yet but did get photos of the vacuum controller and the blower motor controller.

Here's the pictures I have so far and will post more as I figure out why my blower motor is stuck on high at all times.

Controller:






Vacuum controller:














Here's the fan controller: