2003 Trailblazer EXT 4wd V.6. Will not engage 4hi or 4lo or awd.2hi is the only one that works. The lights on the selector Switch blinks over the selection when I turn the selector switch on th dashboard and I can hear the motor but it will not engage the front axle in 4hi or 4lo. The light only stays lit in the 2hi mode. Also the cruise control stopped working. I changed the transfer case/encoder motor last month and still no engagement. I recently changed out the actuator and now the blazer will not drive at all.I can rev it up and get the RPMs but its almost as if the transmission has stopped working altogether. I have checked fuse #8 under the front hood fuse box and also checked fuse #48 under the rear passenger seat. Fuses checked out ok. Would the transmission stop working upon replacing a 4wd front actuator? Thank you in advance for any assistance you may be able to offer.