1997 Chevrolet Astro Owner's Manual - Page 120

The pegs inside the compartment door areused to make sure the button on the compartment door will contact the control button on the garage door opener. Now, with the compartment door closed, press the button again to make sure the garage dooropener operates properly. Add one peg at a time until the garage door opener operates with the compartment door closed when you press the button. With the garage door opener positioned properly and the right number of pegs in place, you should only have to press the button slightly to operate the opener. Adjust the position of the garage door opener and add or remove pegs, as needed, until the opener operates properly. Refer to "Universal Transmitter (Option)" text in this section. 2-46