Hello all, this is my first time posting so I hope to give you all the needed info. Working on a 2000 Blue Bird school bus, has 5.9L ISB Cummins. The issue I'm facing is that the pupil door will only open one direction regardless of what position the switch is in. If I switch the power and ground wires at the door controller relay then the door will only move the other direction. I've verified the electrical in the door controller assembly is good. Tried swapping the driver's switch, but still no change. My boss and I can't figure out why the bus is not removing the relay ground to spin the motor the opposite direction when you flip thr switch. Any ideas on what could be causing this?
Just thought I'd let everyone know, fixed the electrical problem. Went through a lot trying to get hands on electrical schematics. Found the wires at the door relay were all mixed up. Here is the website I found the schematics on. https://vantage.blue-bird.com/Portal/Vantage-Home.aspx
New discovery we made. The main electrical panel, outside under driver window, was needing weather stripping replaced. Water/moisture was getting inside and caused the electric entrance door to act up.