Hey there. If either of you have a 5 Speed...sorry, not too technical...
Be sure that your clutch pedal is lifted up as high as it can go. There are contacts/springs whathaveyou in there that must be touching to properly engage/disengage the clutch and cruise.
I have a loose pedal in my 89 that slips down just enough and all I have to do is lift it with my foot and then cruise.
This might help
