Welcome lweekly to irv2.
To get started here is a Brochure
and 99 Owners Guide
, the lowest we have but not that much different from 98.
Plus its a diesel puller, 210 hp, similar to a gas coach at the time.
If you can look closely at display may have markings of MFG either in front or in back if you drop display out.
If you do that you can check wiring and may have a plug behind display that can be pulled a cleaned with a contact spray cleaner, from RS, after cleaning may get display back. You can check wiring and look for a common ground feeding display may need a re-termination.
If the display needs to be fixed I can find a thread that may help with that.
The dash AC if not cooling that great use a vice grip pliers and crimp one of the heater hoses feeding the AC/Heater unit and see if cooling improves if it does than you could install a BALL VALVE
to shut off hot water into the unit for summer months just make sure wife gets the heat in the winter.
If you know the Vin# or coach build number from Newmar you can input it into the COM_NET2
link and find information for your coach build.
When you find the time come join us down in the Newmar forum.