Gary,
On our 2016 Anthem we are on the third sending unit counting the original.
The second one was replace by Spartan at Charlotte Mich. in April of 2016. This past winter it failed while the coach was setting in our heated garage.
I contacted Spartan hoping they would send me a new sending unit, the sending unit was diagnose as bad after some testing and conversation with Spartan's tech.
Spartan would not send me a new sending unit saying they require a Spartan Service Center to install.
I needed to have the air intake recall done on the coach so I contacted a service center to have both issues addressed.
The appointment was for about the first week in April. So we make in to the service and their tech removed the old sending and installed the new unit. Another tech did the recall on the air intake.
The tech that did the sending unit said everything looked good and we were ready good to go.
We left the service center the following day the first thing I noticed the fuel gauge was all over the place.
After getting home I took the plate off the hole that was cut in the right front storage compartment to access the sending unit. Just a note here on our coach the sending unit is a side mounted unit and they needed to cut a hole in that compartment to remove and install the new sending unit. Spartan had already cut this hole when they replaced the first sending unit.
After taking the plate off and looking at the sending this what I saw.
The tech had installed the sending with the top at the 3 o'clock position rather the 12 o'clock position.
I contacted the service center and reported their error with the above picture. They apologize all over themselves and wanted to know what they could do to resolve their error. I told just to send me a new gasket and would remove and install the unit myself, will not quite myself the DW helped out. Getting the sending unit's arm back in the tank properly take a bit of joshing. Maybe that was the problem the tech was having, but the top of the sending unit is clearly marked.
Gary you need to get the fuel tank below half for obvious reasons and cut a hole in that compartment to replace the unit. The back side of that compartment is plywood. Of course you will need to fashion a plate to cover the hole you cut and seal it up.
The sending is pretty much plug and play.
There is a method you can test to see if it's the sending unit or another issue.
This requires removing the sending unit's plug from the wiring harness.
One of the issues that Spartan looks for is to determine if the sending is getting a ground. The ground point is not at sending unit but at the Spartan control module. The test here is if you have the ambient temperature display in your Spartan message center and the temperature is correct chances are the fuel gauge is getting a ground since they share the same ground point.
Sorry to be so long winded.
PM if you want.
Richard