I have a new to me '98 Blazer LT, 4.3 litre V6. The flasher sounds about 90% of the time, the directional lights are not on when this is happening. The directional lights and hazard lights function properly. It does not sound when the brake pedal is pushed--unless of course you're using the directional signals. I have replaced the flasher with a new one, but the problem still exists. Can you offer up any ideas?

 

When mine did this i had to swap out the multi switch on column. Did yiu try flasher relay?

 

Like WHD says.. very common. {Ever notice it seems to happen more to new owners? Did me, too}

Go to rockauto and look up 'Hazard Switch'. Local stores often sell them too.

If that doesnt work.. pretty expensive, because it's in the turn signal sw {MFS} itself.

 

Did my turn signal today. Bought a Delphi on Amazon for $85.