4x4 question

[kimpaw]

I am new to this forum. I just purchased a 95 sonoma 4.3L 4x4. I was going to convert it to electric and use it as my light duty plow truck / winter driver. I have two other EV's that don't get used in the winter due to what is put on the roads here in Maine. Anyway it runs too well so I decided to put off the conversion and just fix the issues that I have found. I have not been able to find a description of how the 4x4 works. Mine is a lever shift. I guess my question is what happens when I pull the lever to go into 4wh dr? I assume the transfer case is a direct linkage and somewhere the vacuum pot gets a signal to engage the front axle and then the 4x4 light comes on. What I don't know is where the vacuum pot gets its signal from and where is the s/w or relay that turns on the 4x4 light. My light stays on even when I am not in 4 wh dr . What would be a likely cause? It would be a big help if someone could walk me through where the components are in this system.
thanks,
kimpaw

 

[drwet]

I had an '84 with the manual 4x4 selector and I think the light is triggered by a switch on the front axle. When the light is on it indicated the front axle is locked. And you're right there is a vacuum operated engagement mechanism on the front axle. That's from memory - you need a service manual.