i have a 2001 f150, when i start my truck the left turn signal flashes fast i have to toggle the switch to get it to stop, any ideas what to look for to fix problem

 

sounds like you are running low on blinker fluid...


















j/k... i would start by checking out the wiring behind the signal switch, check for a short somewhere...

maybe replace bulbs as well...

 

When it toggles fast, does the blinker actually come on? I had a similar issue with my 97 f150, where the switch sounded like it was going 100MPH.

 

Blinking fast almost always means you have a bulb burnt out, there is not enough resistance in the system to keep the blinking slow. If all of them are good, check to make sure your blinker relay is good.