Fluid level is ok . Here's a question ... What is the purpose of the wires that connect to the brake portioning valve? Could this have something to do with the problem. It appears everthing else works. I just added PS,PB and Auto trans to this truck and the only thing left to finish are these stubit blinkers.

 

I wouldn't know for sure without looking at the wiring diagrams, but it would seem to me that those wires would have something to do with the "brake" indicator lamp on the left side of your gauge cluster. Not sure exactly what it monitors but it does light up momentarily when I start my car.

 

There's a brake fluid indicator switch that those wires connect to, and that switch indicates if the fluid distribution is off. A lot of times though, the switch that goes into the proportioning valve which those wires plug into are faulty. They're made of plastic, and leak, which makes the brake light come on in the cab. I doubt that is the problem with your turn signal issue. I was having some problems with mine, here's the link to the thread on my turn signal/brake issue.
https://www.ford-trucks.com/forums/9...t-problem.html

 

have not fixed it yet i belive it the switch ive tried everthing else i found a switch out of a f4 i hope it will work