This instrument is the best thing since sliced bread for my older Monaco Exec. I apologize to those to already owning one, but I just gotta talk a bit.
The analog temperature gauges on my Exec are not accurate and the ScanGauge D (for Diesel, ya know) quickly pointed that out. Additionally, this four-inch wide unit perches on top of the dash where it's easy to see with its cable going down thru the dash to the diagnostics plug.
It took ten minutes to squiggle under the dash, fish the plug thru and plug it in.
It can be set up to monitor many of the myriad bits of information available on that data socket.
ScanGauge sends along an diagnostic socket adapter for us owners of older coaches.
In addition to monitoring performance, ScanGauge D can pull codes that your engine might be throwing and tell you about them immediately.
For $169.95, this tool is a bargain.
That's their web site.
Let me know what you think!