I purchased two whelen slim-misors and after about two weeks one of them would not flash the patten set on so I tried to change the pattern by pressing the flash button on the back and when pressed the clear would flash but red wouldnt light up when pressed again the clear would flash faster but red still wouldnt flash. when hooked up to a flasher both flashed at the sametime.Any help on how to get the colors to flash at different times?