2004 Z71 Silverado Front Axle Engagement

[bhazely]

I replaced my 1996 Silverado 211k (running perfectly) with a 2004 silverado with 70k on it (2 weeks ago) and launched my boat in a sandy area and my front axle would not engage in either auto, 4 high, or 4 low. The selector switch indicator seemed to function properly by blinking and then remaining solid in each selection. I could hear the rear differential sound of it engaging, but the front tires remained still. After burying the truck I got pulled out and of course fished all day and caught zero walleye. I then got stuck again removing the boat while trying every four wheel drive selection that I had and all selector switch light indicators seemed to function properly. I ohmed the two 4wd fuses that I found and they were fine. I then searched online and was clued in to the front axle actuator to be suspect and then decided to replace it. The front axles still did not engage, I guess my next step should have been testing to see that the actuator extends. So I installed the old actuator and removed the new and found that they both extend properly. Any ideas on my next step?