Why does my fuse keep blowing after I start to drive my truck?

I drive a 76 ford f100 and every time my truck is parked and I put a new fuse it all the blinkers work well but as soon as I drive my fuse blows could it be that I have very bad wiring of that i have an open circuit?

If you're blowing fuses,… You got s " short ", in the turn signal wiring

AFTER the fuse blows you have an open but it's a short somewhere in the blinker system that causes the fuse to blow.

Check the grounds on all lights (Brake and Front Turn), does it have a trailer plug, check the plug where you are spliced in and the connector where the bed plugs into the main harness, I suspect you will find a broken wire, bad ground, or trailer plug causing the issue.