blinker/fuel gauge issue??

Yes, it sounds like there is a short in the instrument area or rear harness as suggested, with higher voltage than the 5v (nominal) regulated instrument voltage getting to the fuel tank gage circuit.....although it seems this woudl likely effect the temp gage too if it were in the dash area.

IMO, you need to be jumping on this NOW! Any shorts are a BAD sign.....and can have BAD consequences if left unfixed.