4x4 question
 

when i push my 4high button it will just sit and blink for forever and a day.
when i push my 4low button it will go into low but stays blinking as well.
when i push my auto 4x4 it will blink for a bit and then go back to 2 high.
isn't the light supposed to go solid after it gets into 4x4?

i am thinking my hubs are not engaging, am i correct in this thought? i was reading one of the 4x4 threads and there is something to check on the hubs or front axles, but i cannot seem to find that thread again. anyone got any hints for me?

RE: 4x4 question
 

you have to be at a certain speed for4HI to work. you have to be doing atleast 30mph, and 4LO you have to be barely moving. and to disengage 4WD back to 2HI, you have to be moving aswell.

RE: 4x4 question
 

it stays blinking when i am going at said speeds.
i am pretty sure it is engaging on the transfer case, at least with 4low it is. but i am unsure about the hubs. sice it stay blinking

RE: 4x4 question
 

hmm well from my knowledge it shouldnt stay blinking if it is engaged.

RE: 4x4 question
 

thats what i was thinking, i know 4low goes in on at least the transfer because it is nice and low when i try to drive around

RE: 4x4 question
 

mine does the same thing,are yousure the front wheelsare engaged in low, i had the sameproblem and 4low seemedto work, well got into snow the day and tried it out, and just spins rear wheel in low, and i ahve all the same symptoms as you,does anyone know what is wrong?

RE: 4x4 question
 

blinking means its not engageing and its going to go back to whatever gear you where in before, in your case 2wheeldrive.
Could be your dash switch or TCCM.
No the front hubs are not the problem, the axle is permanently locked to teh hubs.

You can be in any speed and engage 4hi. I do it all the time pulling into my yard, pop the front tires up in the grass, and push 4hi so I dont chew up my lawn. I am barely doing 2 mph when I do this. You can pop into and out of 4hi at any speed.

4lo- you must be in neutral and going less then 5mph. slight movement helps it mesh, but is not neccessary.

find the threads in teh Do-It-Yourself section. There are two of them. One on the vacuum system and the other on the electronic portion.


read some more posts in this thread.
I wanted to add this.
If your getting into 4lo then your TCCM is working and no doubt your problem is either the vacuum switch or the vacuum actuator, or one of the hoses is leaking vacuum.
Read this
https://blazerforum.com/m_52228/tm.htm

RE: 4x4 question
 

thanks i will give that i shot, i just replaced some of the hoses on the vacuum system as they were causing my SES light to come on. i will go looking and see if i can spot any of the things in that thread.

RE: 4x4 question
 

well yes the 4lo enages but doesnt engage frontwheelsso still blinks, and im sure 4 hi engages but doesnt enage front wheels whic makes it the same as 2 high. today i pulled battery out and tested i bilieve it is the diapram by undoing vacuum line and pushing in diaphram to see if it holds suction, and it did.so does that ,mean my vacuum switch is bad?