4 x 4 not working

[bjbrh1]

I have a 99 4 x 4 Suburban and transfer case not shifting. It wasn't working so I started at the common problem and replaced the dash switches. That didn't help so I replaced the module under the dash. Again no luck. I replaced the transfer case motor and everything was working great. The next month, I installed a 6 inch lift and the truck was on blocks for a month. I did have to drop the front differential. When I finished putting everything together, I had the exhaust relocated and installed the front driveshaft. When I tried to switch it, I get no noise or sound from the transfer case shifting. All I get is blinking lights on my switches. Thought I had a bad transfer case motor so replaced with another new one. Still nothing. In 2 high, the front driveshaft turns freely and when I hit the 4 x4 switch, the lights blink but the front differential locks and you cant turn the front shaft. I have double checked all the connectors and they are all hooked up. What would be keeping the transfer case from shifting when it was working great before I installed the lift

 

[Frank Enstein]

It might be the sensor lying to you. I believe there is a sensor on the transfer case that tells weather the transfer case engaged like it was supposed to or not.

Get a service manual and a decent ($50-60) multimeter and follow the test procedures.

It might be as simple as the sensor got unplugged.

Jack up 1 front tire until it is just off the ground when 4x4 is engaged and try to spin the tire.

If it's engaged the tire won't spin by hand.