help ac dont work?

[6.0stroker]

I have 2005 f250 6.0 with 108k and my ac wount work at all blows hot air. It is throwin a code, po645, please help

 

[bigugly78cj5]

Check your a/c clutch relay fuse. and the relay itself. odds are your fuse is bad, which is usually caused by a bad compressor clutch field shorting it out, usually anyways. Ive seen belts coming apart causing a short in the wiring and even compressors locking up causing it...

 

[6.0stroker]

Where can I find that fuse at?