I have a 2000 tahoe with a blinking 4wheel drive selector
the two wheel drive seems to works fine
but when I press the button to go into auto 4 wheel the light flashes
and returns to 2wheel drive
when I try 4wheel high it seems to work and stay blinking
the truck does steer like the truck is in four wheel drive
when I try 4wheel low the truck acts like its in 4wheel
it turns choppy like my 2002 2500 HD work truck
but the selector light still flashes never going steady
what would be my best way to check the selector switch
and actuator
and transfer case motor

 

Maybe a conversion to a manual shifter might be in order.

You never see a post that says "My manual 4WD shifter is stuck.".

 

I hate the electronic shift transfer case a couple of months back the encoder motor on mine went out and they are not cheap. When it did i could shift it into 4 wheel high but not 4 low it would just keep blinking and then go back into 4 high. I dont really know of any way to test that stuff to see what has gone bad about the best thing that i know to so is to start with the cheapest thing and work your way from there. About the only way that i know of to check the actuator on the front diff is to take it out and have someone try to put it into 4 wheel drive and if it engages then it works. Or you could take it to someone to see if they could figure out what is wrong with it. I will never own another truck with the electronic shift 4 wheel drive it will be the floor shift.

 

The selector switch is what the most common cause is for this. I have seen some guys have luck with unplugging the switch, then reconnect it and problem goes away. If it comes back, definately the switch.
Kevin
www.PartsTaxi.com

 

When I was in the Navy we had a couple of pieces of "equipment"(a kind word for these sewage plant refugees) which had electrical-switch-activated-solenoids. Very similar to the (you guessed it) switch-activated-solenoids on electronic 4WD dash shifters.

Long story short, the solenoid actuating rod(relay/coil activated rod which actuates the shift mechanism) freezes, or sticks. By Detroit standards, the military solenoids were 10 times better than GM OEM, and they still bound up. Four years on that ship, and they never satisfactorily upgraded that equipment; so, of course, we sailors had to operate ALL those "automatic" switches MANUALLY.

Needless to say, when it was time to select a vehicle with 4WD, I took one look at the pushbutton mechanism on the dash and said to the salesman "So, tell me more about the Manual 4WD selector for these models..."

 

The dealer or a tech with a Snap-On scanner can scan transfer case, Transmission and body computer to see what is going on