PA450um Won't Pair Bluetooth

I have a PA450um marine stereo For some reason it just says "pairing" for a while but nothing happens. I've tried to pair with several different phones but it just won't pair with any device.
I've tried setting resetting the PA450um defaults. I've turned on and off then on again the Bluetooth still nothing. The Bluetooth audio was working fine but just stopped. All the other functions work fine.
How does Bluetooth pairing break?
My IPhone never even sees the PA450um. I've even turned on then off and on again the Bluetooth on my phone.

Answers