1993 Monaco Dynasty Transmission

[Bigoexpress]

I have a question about a Allison 6 speed in a 1993 Monaco. I looking into buying this coach but the owner says the transmission works good( has owned it for 14 years). But he says it doesn't go into gear. I haven't seen it yet to see if the lights are going on on the shift selector. But do I have any ideas why it's not going into gear. Battery cables/grounds /not enough batteries? It's starts and runs just doesn't shift into gear. Any advice will help. I very mechanically inclined so any advice to put me in the right direction would be greatly appreciated

[Skip426]

Welcome to iRV2.

The issue maybe engine idle speed .
The trans controller won't allow a shift into gear if the idle is too high ( 750 RPM if memory serves) .
A 1993 engine is probably a mechanical Cummins and broken throttle return springs or rusted and binding linkage are possibilities.

Can you confirm engine size and trans series ?

If the trans shift pad isn't powered up usually the engine wont start.

[Bigoexpress]

The coach starts but no lights light up on the shift indicator panel.

[johnhicks]

https://www.transmissioninstruments.com/

[Skip426]

First thing to do is locate the VIM ( Vehicle Interface Module) and check the two internal fuses.