One other note on Centroid - when I talked to them, they asked if I wanted to troubleshoot the sensor. At the time I said no, but after thinking about it I thought why not? I emailed them back and they sent me some troubleshooting instructions. If you are interested in the same, just email them that you want to troubleshoot the sending unit on your Monaco coach. It sounds like they were only used up to 2007.
As I am somewhat in transit, it may be a few weeks until I can get around to looking at mine.