check the electric connection..... I had that once too...yrs ago...loose connection, reason I did nt think it was too hot, I have an aftermkt temp gauge also.

also, see if it kicks out water after stopping the engine...
and if you have a stock system ,make sure its not filled over 3" down from the neck when "full" at cool...
the electric 'idiot' light shouldnt come on until about 245F or more I think...so just red flickering light is probably not over heating