I have a 1999 with the three button dash switch.

Unlike most posts I've read about the switch lights blinking(which I have experienced), my lights are flickering wildly and are inconsistent. I believe its in 2wd most of the time but lately its been driving weird and jerking alot especially up hills and the flickering has become more and more apparent. Also, when I push the buttons nothing happens. I have recently changed the seals and vacuum switch and have looked at the actuator, all of it seems fine.

Any thoughts?

 

Could it be the the control module or motor? And are there any ways to pinpoint it?

 

Quit for a while and started again. I cleaned all the connections. The lights still either flicker or are all off.

 

I had a similar issue with the lights, I replaced the switch with a Delco part I found on eBay. It solved my problem.

 

so if the lights are off and it wont engage the 4x4 what should be the first thing i look at?
i have an 01 zr2

 

Check and clean the TCCM. Check the connections to the switch sounds like they are loose or you have a faulty connection.