Push button 4 wheel drive when engaged in 4 lo or hi and try to engage back into 2 hi it clicks tccm didn't looked corroded 4 wheel drive push buttons replaced vacuum switch seemed fine however if I turn the wheel sharp sometimes it'll click into 2 hi

 

Does the 2HI light on the switch come on when you select 2HI?

If so, it might be a sticky actuator or cable under the battery tray, or could be the mechanism in the right front axle has a problem.... broken spring etc.

 

I took the battery and tray out and the diaphragm (is that the actuator) looked ok it was in 4 wheel hi when I did that and it was sucked in if that makes any sense lol I just didn't know what else to try or what I should replace, I was hoping I could narrow it down since if I turn the wheel sharp hitting the gas and hit the 2 wheel drive button itll usually go in

 

In 4WD it should have vacuum. In 2WD there should not be any vacuum on the diaphragm of the actuator. If it's sucked in, (in 2WD) that's why the front axle remains locked in. On your 99 there should be an electro-vacuum switch, just about center of the firewall, under the hood. Looks like this:





With the engine at idle, 2WD selected, one port of the switch should have manifold vacuum. The other port goes to the actuator and it should be vented to atmosphere. In other words, you should be able to blow & suck on the port with very little, if any, resistance. When 4WD is selected, the 2 ports are connected together inside the switch, which will apply vacuum to the line that goes to the actuator.

BTW, the switch on the dash, does it have 3 buttons, or 4?

 

It has 3 buttons so it's not a auto 4wd, so I should check that switch?

 

Yes. At idle, 2WD selected, remove the vacuum line that goes to the actuator, there should not be vacuum at the port on the switch. Then select 4WD, there should now be vacuum at the port. Post your results.