My 4wd doesn't work on my 1996 chevy blazer. The light comes on and stays on and acts as if it shifts into 4 wheel but the front tires don't pull. We jacked it off the ground to see for sure.
Helpful video for troubleshooting 4 wheel drive issues with the Blazer: https://www.youtube.com/watch?v=IP0jhBG0jv4
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