David,
Yes, it was Ralph's. And they hooked the camera at the back pf the truck. After some research, I did some continuity checking of the wiring from the camera connection to the cab, and it appears the ground has continuity, while the power and video wires do not, so to my layman's mind that means the issue is likely in that cable.
I will be returning to Ralph's to see if they have a replacement that I can configure to fit my system. They don't sell just the one cable but sell it in a package with the camera included (which, if my camera does work, means I am buying something I may not need, but oh well).
It also means I will have to remove the dash panel and pull out the head unit to get at the video cable, not something I wanted to do.
Thanks again for your continued assistance, and offer of help.
Regards,
Marv