If you have removed your cruise control box, or if you suspect it may be bad, your O/D will not work. Basically, your O/D trigger wire runs through your cruise control box, the one behind the passenger side kick panel. With that removed, or malfunctioning you will not have O/D. You can jump between the terminals and gain back your O/D. Let me know if you want to try it and I'll take a pic for you.