[Richard]

I have had flaky issues with both fast idle and the step so I don’t know if there is a connection to the Allison work.

If I interpret your post correctly you ran an check transmission test which should have caused the transmission light to flash. It didn’t. The bulb is confirmed good. But no power to the bulb when the test is activated.

If that is true then I would call the shop and speak to the service manager. I would ask “ what should happen when I run the test transmission light?” Of course it is supposed to blink . I would calmly explain that you were just in for service to clear a transmission code and you don’t understand why the light is now non functional. Then I would say that before I made a perhaps erroneous conclusion would he like an opportunity to look at the coach again?

I know it’s a bit of a trip .....