I have not seen this answered,i replaced multifunction switch a while ago and now the blinkers flash fast and front and back both sides blink and I just replaced the flasher with a GM one,same thing happens..i had LED headlights in,but I removed them all except the fog lights...do I need another multifunction switch?

 

Usually hyper/fast flashing/blinking is a sign of a bulb out. If any of your blinker bulbs are LED, odds are there is a resistance issue that causes the flasher module to respond like a bulb out.

 

one of the wires in the rad support ground was hanging on by thread..respliced them on and problem solved,but something is clicking under the dash..went on for like 4 min the other day,like morse code..