When close call is active, I can see (very) high signal strength for a band but the radio does not break squelch. Even with squelch set to '0' I will not hear anything despite a signal being received. Do I have to have a service turned on to hear? (which would not make sense). I do receive signals that will break squelch so I know CC is working. Thanks in advance.
I'm definitely not able to understand what do you want to mean...
In Close Call Only mode, above each band number the 436 displays a vertical bar whose lenght is directly proportional to the signals strength in that band (for example, on the hateful

band 1), and then?
As far as I know, the squelch has nothing to deal with a Close Call Capture:
a CCC is triggered only when a nearby strong signal rises above the local EM background noise of at least 20 dB or more, thus in CC Only mode it's just normal not to hear anything, until a nearby strong signal is emitted.
On the other hand, if you are monitoring some channels and with the CC DND or CC Priority modes active there is no audio despite the squelch set from 2 to 0, then maybe there is a hardware failure...