When I push the 2-wheel button, it continues in 4-wheel drive for another minute or… Check to see that the wheels are locked don't bother to see if the wheels are locked your truck does not have manual locking hubs. Exactly where I am also trying to find out. When it heats, the pin in the end swells and pushes a shift fork in the front differential. The 4wd didn't work so took it too a shop and had everything replaced, pertaining too the 4wd. I couldn't tell because the electronic axle switch was bad as well so the lights on the 3 button 4x4 control all looked perfect, e.
A temporary check that you can do, is service replace and or top off if low the fluids in the transfer case and front differential. When you find it-unplug the 2 connectors and looks for green corrosion on the terminals in the plug and also on the module. The differential carrier assembly uses a conventional ring and pinion gear set to transmit the driving force of the engine to the wheels. My was located in the middle of the firewall. Mine went into low range, but my front axle wouldn't engage.
The other possible problem is the hub itself. I replaced all the vacuum lines and the vacuum switch. One other option for the front diff that many people discount is to disconnect the actuator vacuum lines from the t-case and install a manual operated vacuum switch. Neither do parts in the transfer case. I use mine at least once a week and it failed when we got a foot of snow.
I have tried driving around with the light flashing to see if it would engage it did not. It's likely that they told you the most common failure and left it at that. The thing that has been the problem is a vacuum actuator under the battery box that engages the front axle and it ruptures the diaphragm and stops working. This causes it to work some of the time , or not at all. I think this becomes more of a trust issue than a mechanical one. Guru5F123 answered about a year ago Try replacing the Transfer Case Control Module or unplug the wire harness from it and spray some electrical contact spray in to clean the wire harness and force some dielectric grease in the ends of the wire harness. If it switch's it may not switch back or worse off it may switch… On the front differental there will be a tube looking thing about 6 inches or so long sticking out of it.
I would select 4 hi and it would shift andI could confirm it was in 4x4. I took the switch off leaving the lines on the switch pushed the ball in to activate the switch. Don't always assume it is working because it moved when put in 4x4. Make sure your actuator and cable is working good first thing. It worked for my Blazer. First, so you are sure it will work when needed, and secondly, to keep everything lubed.
Thanks Could be many things. Sensor Switch is on drivers si … de engine block. Most common cause for it to not go into 4x4 is the vacuum actuator. On a 1998 Blazer you can replace the bearing Hub assembly yourself! The pads may be frozen to the bracket. I have tried the fuse thing, tried the neg. The Chilton's manuals are pretty good - but they are not perfect.
It has the 3 button dash switch 2 wheel 4 hi 4 lo when you push the 4 high the 4 hi and 4 low blinks a few times and both lights turn off. Reverse the process to re-install the components. First check to see if the transfer case is engaging, You can do that by switching to 4X4 and then seeing if the front driveshaft is locked in. The way this actuator works, is it is a sealed chamber that gets heated by voltage. It has o-rings that go bad… 1.
If the electronic shift motor is not connnected will the front end still engage? After 4 mechanics it is still not working. A propeller shaft connects the transfer case to the front axle. They lubed as you drive all the time. The fuel pump is located inside the fuel tank. Just jack one side off the ground. Take it to a mechanic.
Wire 50 brown is the 12v feed, and it conducts to the light blue wire 900 to the actuator. Problem: clicking sound while in 2wd at low speed. You can manually pull the cable and see if the front axle locks in. When I drive forward or reverse in 4 hi it sounds like the 4wd is trying to engage but cannot or is not meshing gears properly. My transfer case seems and feels to shift fine by hand and locks in when I use a screw driver to lock it in manually. I have a 98 Blazer 4x4, bought it about 2 years ago.