Hello, I am new to the forum and have a 4x4 issue on my 1999 Blazer. I have read through previous threads on the problem and am still lost. I followed the vacuum lines from under the battery and found that 2 lines by the driver side of the vehicle had dry rotted lines. Replaced those lines hoping that would cure the problem and of course it didnt.

A little background: When trying to engage 4x4Hi on a 4-button system, it will just blink and blink and blink and will not engage. When in nuetral, and tryin to engage 4x4Lo, you can hear the transfer case try to engage, but still it just blinks and blinks. All the fuses are good. The vacuum under the battery seems to be working fine also. What else could be the problem? Trying to fix it myself and avoid a rediculous bill at the dealership. Any help would be appreciated.

I know there have been many threads on this problem, just cant seem to find what would apply to my situation. Thank you in advance for any help. And being from New Jersey, looks like we are going to get spanked with snow again tonight into tomorrow and I have no 4x4 : (

 

Will it engage if you are slightly rolling forward or backwards with the transmission in neutral? Does the front axle actually engage when the lights are blinking?

Have you removed the TCCM and checked the electrical connection?

Have you tried disconnecting the battery for a bit to reset the TCCM?