93 updated 4wd actuator on axle

I enjoy the Colorado winters with the Suburban but the 4wd is not working this year. A friend of mine told me that his needed the thermal actuator replaced in the front axle a few years back. I went down to purchase the parts and found out that the actuator had been updated to a solenoid style with a new wiring harness. I purchased the parts and then discovered that the actuator, pn26060073, was already on the vehicle. It is a 3 wire connector with switched power on one of the wires when I put the t-case in four wheel. Can someone fill me in on what I should have at the connector or how to diagnose this? Just for grins I hooked the new actuator to the harness and it didn't do anything when I put it into 4wd. I'm feeling real stupid for not properly diagnosing this before I went and bought the parts. This burb has been bullet proof and is at 197k. I look forward to it reaching 200k. Thanks, Michael

do the lights flash on the buttons when pushed, or do they just sit there doing nothing. would be best to get a good scanner on it at this point.

Thanks for the reply. My suburban has the good ol reach for the shifter on the floor and move it in to 4hi or 4lo. No buttons on the dash. If I remember correctly there is a light on the floor shift bezel to indicate that the vehicle is in 4wd, it is not comming on either. I like your disclaimer though. LM

This is for a '94 and should be the same for your '93. This is also for the stock 2 wire thermal actuator.

Power is supplied by the 4WD fuse in the I/P fuse block. When you select 4HI or LOW a switch in the T-CASE supplies the 12v to the actuator solenoid. When the front axle locks in the solenoid switch sends 12v to the 4WD indicator lamps.

So 1st thing is to check the fuse then power into the T-CASE sw on the brown wire with the key in RUN and out of the T-CASE sw on the light blue wire to the front solenoid. Hope this helps.

Hey 777stickman, I think you were right! I see that your post came the next day and I should have checked my posting but I had to have the oil changed and while at the dealer I asked them to check it out. They replace a transfer case switch, pn15693423, and then diagnosed the new style actuator was stuck and replace it too. I have questions that the new style actuator was bad and I failed to ask for the old parts returned to me so it "is what it is". The lesson I learned is to be more patient with my postings and to get my old parts back if someone else is doing the repairs. Many thanks, LegacyMan.