2001 ZR2 4wd won't engage

New parts list
-new encoder motor
-original kick panel modual and a junkyard
one neither fixed thw problem.
-new dash switch (3 button)

With motor running and in neutral push the
4hI button and the 2hi light stays on while
the 4hi light blinks a series of times and u
can hear the modual in the kick panel
clicking but it stays in 2hi. Took the battery
out and the tray and the vacuum boot seem
to all be in tact, no tears. Even pulled the
diaphragm back and zip tied and tried it and
still just binking. Please help.