David,
Thanks for the response.
When you say the defect probably lies in "that unit", I presume you mean the plug?
The camera has a short (couple feet) wire which connects (by a very small plug) to a wire which runs under the truck and into the cab through the firewall. You may be correct about where the problem may lie, but I am hoping someone can give me some advice on how to determine if that, or another location, is where the issue is.
As to buying a new camera etc, the truck is getting close to end of life and will be replaced early 2022 (supply dependent, of course), so I was hoping to fix rather than replace at this point (unless it is unfixable and needs to be replaced).
Thanks again,
Marv