Should have mentioned that the way I knew the multi switch was bad was to simply check the resistance thru the switch.

In the right turn circuit there was no resistance equals good.

In the left turn circuit there was high resistance which equals a bad switch.

50 bucks for a new switch & a couple minutes to install it & problem solved.

As the other guys mentioned the fast flashing is caused by high resistance somewhere in the circuit. Find that & the problem goes away.