763 bobcat Gauges spike when I turn the lights on

Pretty much says it all in the title.. IM currently fighting with an electrical problem. Seems when i turn the lights on the fuel gauge and temp gauge run higher then they do with the lights off.. Seems like a ground problem but I cleaned all the smaller grounds by the starter and the 2 main grounds as well. I also cleaned the battery connections and checked all the connections under the cab. also found a ground by the hydraulic tank and cleaned that as well.

Did i miss...

763 bobcat Gauges spike when I turn the lights on

763 bobcat Gauges spike when I turn the lights on