i have 04 wrx and its stock. my head light is getting wierd. when i'm driving at night i notice that the light dim and a quick flash and back to normal. it doest that i say maybe every one minute or two.
does any body know what wrong? what need to be check? i check my ground and nothing was lose. i also clean the bettery terminals.

thanks for advance.

Check to see if there is a problem at the light socket first. If that is ok then check the relay for the light. You could try swapping it with the right side one to check it.