Q: IPhone 5C won't pair with IMac

Attempted to pair IPhone 5C with my IMac (14GB memory, 10.9.2, 3.5GHZ)  but it first connected then disconnected.  Now it gives me a message the IMac is out of range and cannot be connected.  It did connect when I turned hotspot on in the 5C, but disconnects when hotspot is ended.  Have tried many solutions via the net, but none have been successful.