Looking for ideas, before I bring my truck to the shop.

1997 K1500 Z71
5.7L V8

When I press the 4high button, the 2wd light flashes, indefinately.
If I dont press the 2wd button again, it will not stop flashing.

I purchased the truck in 2004 (June), and am not sure if the 4wd was ever used.

Any ideas?

Check the #25 fuse in you fuse block near the drivers side door. If that isnt blown check the front axel accuator located on the back side of the front axel. See if you are getting power to it. If so replace the acuator. They are about 80 bucks and come out like a big spark plug. Good luck

My '96 did the same thing a few weeks ago. It was the actuator on the front end. DO NOT get the stock one if that is what it is. There was problems with those heat activated units. You can get the up-dated actuator (I paid $135 at the dealer) & it will work MUCH better than the stocker. GM issued a TSB on it but did not do a recall.

Edit; Put "Actuator" in the search box, there is plenty of info on it.
BTW it is fuse # 24. Good luck!