4x4 help
 

hi i have a 02 s10 4x4 and im having some problems. when shifting from 2h to 4h nothing happens, the light blinks but then stays on but it is not engaged. the shifting into 4l i can feel and hear the tranfer case engage but it is still not in 4wd. any help?

when it is in 4low and you drive it, does it drive like 4low or like 2hi? does it throw a 'check 4wd' light on your instrament panel?

you need 2 things to enguage for your 4wd to work, the front axle and the t-case.

if it is like 4low when you drive around, then it is something with your front axle enguagement... I am having problems with this in my 01 zr2 blazer right now. it can be a bad vacume line, check right on top of the brake master cyl, that line always goes out. if that is good, check if it is holding a vacume at idle. if it is, then take the battery and batt tray out and with jumper cables start the truck and put it in 4wd and see if that vac actuator pulls the cable. it can be a vac switch under the winshield wipers and on top of the distributor in the eng compartment. it can be your cable that goes from the vacume actuator under the battery to the front axle. that is the problem that I have with my blazer, its a PIA to fix.

if you drive it in 4 low and it feels like 2hi then your t-case isnt enguaging and it can be your electronic shift motor, a vacume line, or the switch.

when testing if it goes into 4low, give it some time and go between neutral, D, and reverse while inching back and forth to give it time to fully enguage the t-case.

PS, i think these push button 4WD that GM designed are a huge POS, gives me more problems then it has given me convinience. and it is impossible to convert over to a fully manual 4wd without doing a solid front axle swap.

I'm not sure on the 02 models but if your solenoid goes out on the front end it will not engage the front axle. Most of the time it's the solenoid, but have seen the wires be the problem due to going 4X4ing and them getting caught by something. Again check the solenoid as this is the most common cause.

where is that solenoid? i see one on the firewall, a small black one, is this it? how do i test it?

yep thats the one. you can test it like I said in my prev post by seeing if the vac actuator under the battery moves when you push the 4wd button. or just hook up a vac guage after that switch and push the 4wd button, if it shows vacume then it is working fine.

I'm not sure about that 1 being the right solenoid. And the vacuum style wasn't on the later s-10's as they went to electric soleniod. You should be looking at the front rearend, and it should be on the pass. side of the 3rd member. It will have wires plugged to it. Have some one to try pressing the button while you listen or feel to see if it makes a click or clang. If it doesn't then check to see if it's getting juice. If so, then replace it and your ready to go again. Hope this helps.

hey insane4fbodys, you're right that solenoid doesn't have any type of vacum lines to it, and mine is an electric shift type model. there is a switch on the side of the 3rd member the vacum hose that pulls on the actuator and there is a switch with a harness is plugged in. this is the switch that needs checking?
there is no check 4x4 light coming on either so there must be some minor thing im not seeing

My 2000 ZR2 had a similiar issue and it was the electrice solenoid that has been discussed. If that does not do it, I would then check the switch in the dash.

Most of the time when the light shows it's in 4 wheel drive. tThe signal comes from the transfer case showing it's engaged. Sounds as if everything is working besides your front solenoid. The switch/solenoid you have found on the 3rd member is the correct 1. Chances are if replaced, you will have 4 x 4 operation again. But again check to make sure you have current to the plug end when in 4by mode. If so replacing your solenoid should be the only thing you'll need to fix.