KP2

Thank you. The transmission is an Eaton 9 speed. I found a E-7 overhaul manual on Ebay so that is a possibility. I think maybe an owners manual that would layout what instruments were in the dash and just general information would be a help. The wiring behind the dash Is terrible. I really need a wiring diagram to try to work that out but in the end I may have to rewire to get the basic things working and be happy. I see books for 1997 RD and later but not the 1992 to 1997.

I have been searching for manuals and wiring diagrams for my truck and the only ones I see(manuals) that may work are on eBay. The manuals are for a R600 truck. I am thinking that this is the 600 series and would include the RD688. Don’t want to buy the wrong manuals so any advice would be appreciated. Thanks.

Thanks for the followup. I just bought a 1992 Mack RD688s and I am working on the interior lights.