Fuel gage 1965 comet

[flathead 53]

My fuel gage in my 65 caliente reads a quarter tank higher then actual amount of gas in the tank, If you turn ing switch to the left acc the gage reads the correct amount . When you turn car on or just turn key to the right ,it reads a qtr tank higher. the car has a new sending unit,And I changed the small voltage regulator thats on back of the gage panel ,don't see how the gage can have two different readings.

 

[dmsfrr]

Is there a chance someone else has been into the dashboard or Ign switch wiring?
My first guess is the fuel gauge is getting the correct regulated voltage from the Acc position of the Ign switch but might be getting full voltage the rest of the time.

 

[miker98038]

X2. First I’d check the voltage into and out of the regulator, and if it’s different there, I’d check for a failing ignition switch next. Does seem like if it was in the sw itself the voltage difference would be showing up elsewhere too. Temp gauge read the same either way?