RE: How do I program the garage door opener in the Blazer?
I just did this to mine. Lenny is right if you have an older opener, but if you have a newer garage door opener, it probably has the "roaming code" feature described in the owner's manual. Your garage door opener should have a button on it (mine, a Craftsman, was a white button on the backside of the opener opposite from the garage door).
Push the button on the opener, and then within 30 seconds, press and hold one of the Homelink buttons in your truckuntil the blinking changes from slow to fast.
2000 LT 4x4
'81 Harley Sturgis Lowrider