Seat Belt?

My 2005 crew cab seat belt is 'permanently' retracted. Don't know why; no accidents. It's the integrated into the seat back type, rather than post mount.

I can't find a replacement, even an actual Ford part, that has the electronic sensors. Does anyone know of a source? I'd rather have it done, but unfortunatley just don't have the $650 they want to do it.

If I install one without the sensors, it may affect the air bag?

Thanks...

Gary