Q: 4WD is not engaging on my1997 Chevy Blazer

asked by on

I recently discovered that my 4wd has stopped functioning. I have replaced both the actuator under the battery tray and the actuator valve on the transfer case and is still non-functional. I can hear the transfer case switching to 4hi and 4lo but it does not lock the front differential. What is weird though is if I want to go over a curb, I can put in in 4lo and I can feel the front wheels pull the truck over the curb. But if the rear wheels spin, it immediately disengages. I tried to get out of a muddy field and I put it in 4hi then 4lo but only the rear wheels were spinning. I don't know what else to check. I really need the 4wd since I live in a snowy region. Any help is appreciated.

My car has 98000 miles.
My car has an automatic transmission.

Hi there. The problem with the transfer case can be caused by the encoder motor/transfer case motor loosing power, the transfer case engagement switch failing or loosing power, the vacuum actuator under battery tray loosing vacuum, the vacuum actuator valve leaking vacuum on the transfer case, or a broken cable from actuator to front differential.

Since you replaced the actuator under the battery and the actuator valve on the transfer case, then the problem lies within the motor on the transfer case, the transfer case engagement switch in the cab, or the cable that runs from the actuator to the front differential. Check the switch in the cab to make sure that it has power and is keeping power while in 4x4 mode. If there is power and the switch is okay, then check the motor on the transfer case to see if it is coming on.

Check for power on the harness to the motor and ground to the harness. If the harness is good and there is power and ground but the motor is not working, then replace the motor. If the motor is working, then you need to replace the cable to the front axles so it can engage and lock the front axle. If the cable is working fine, then you may need to have your transfer case rebuilt or replaced (if all options are exhausted). If you need further assistance diagnosing your transfer case, then seek out a professional, such as one from YourMechanic, to help you with your vehicle.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. 4WD is not engaging on my1997 Chevy Blazer

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My SUV is has multiple misfire p0300. Plus it also has two more codes for the secondary air too?

Engine misfires can be caused by many different problems and are generally caused by either a spark or fuel issue or in some cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft...

Q: Engine mifiring at higher RPMs, tachometer spiking up

Try to replace the ignition module and coil which is mounted top right side of the motor. The ignition module supplies the tach signal and the coil supplies the spark to the plugs. It is a good idea to replace...

Q: How do I check and change the transfer case fluid?

The transfer case fluid keeps the transfer case in good working order. The inspection and changing of the transfer case fluid is important to the maintenance of your vehicle. To check and change the transfer case fluid. Clean transfer...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...