2001 Mazda 4x4 no vacuum hubs will not engage in four wheel drive B4000

This vehicle has no vacuum lines for the
hubs the hubs turn all the time it just does
not engage the four wheel drive the tccm
lights up when you start it but when you turn
the switch it doesn't say anything unless it
actually engages and sometimes it does
when it doesn't engage the light comes on
when it doesn't engage the light stays off
when it does gauge I hear a clicking sound
before it engages when it doesn't engage I
hear no sound is there some sort of solenoid
or relay switch that is not functioning
properly between the switch in the inner cab
and the transfer case I've checked all the
fuses all the relays feasible links diodes
everything passes as functionable should
work but I cannot engage it all the time and
most of the time it doesn't engage I know it
has the transfer case motor which I have
power going to I haven't bench tested yet but
the reason I have it is because I'm not
hearing the clicks it's got to be something
engaging it and I don't know where it's at any
help I can get I'd appreciate it very much
thank you