The vacuum actuator is either in the fender or under the battery. The actually diff actuator is on the back/bottom of the front diff. Mine (2000 blazer) is under the battery. It sucks to get to.
If you check the actuator and it doesn't move at all, check the vacuum, if it's not getting vacuum, check the switch on the top driver's side of the transfer case. It sends vacuum to the actuator. It has three vacuum hoses coming off of it. It costs fifteen dollars at autozone and usually greatly improves the performance of the acuator.
Under your battery tray
There is a switch on the transfur case that sends power to the front differential 4x4 Actuator when you shift the 4x4 lever,need to check the switch with a test light to see if it has power going to it. If not then check fuse in fuse box for the 4x4, If it does have power going to it, then go to the front housing and check the Actuator with a test light to see if it has power going to it, if no power then problem is in the wireing from there back to the transfur case switch. If you do have power at the front, then replace the Actuator.
What year is your blazer? Most common cause for it to not go into 4x4 is the vacuum actuator. The actuator is run by vacuum from the transfer case. The vacuum compresses the rubber diaphragm which pulls a cable on the front differential to lock it in. The rubber diaphragm is prone to break down and if there are holes or tears in the rubber it will only suck air and not have the amount of vacuum needed to pull the actuator cable. This actuator is commonly mounted under the battery tray. Easy to remove and inspect. 1998 blazer There is a vacuum switch on the transfer case that usually goes bad. I have replaced mine 3 times. Factory lasted until 225,000 miles and had to replace the aftermarket 2x since, one only lasted a year.
The fuel gauge fuse on 1998 Chevy blazer is located in the front of the blazer. It is on the driver side next to the hook latch.
near the front differential
on the intake manifold front of motor on top
Need to know what is wrong with it to answer that question.
very very hard
Where is the blend door actuator on a 1998 Sonoma
The ERG valve is located on the front of the engine on a 1998 Chevy Blazer V6 4.3L. It is near the top bolted to the intake manifold.
There is no differential. The transmission is both a transmission and front wheel drive trans axle. It is all in one.
On the front axle, passengers side of carrier housing.