There is a small rubberized spaced that is located on the upper level of your brake, near the top actually towards the steering column. You will notice a push switch that makes contact with the brake. If the switch is outward it will not allow the cruise control to engage. The small rubberized piece keeps the switch pushed in. Over te the piece becomebrittle and breaks away and allows the switch to stay open. Here is the Nissan info: Order these parts from you Nissan dealer.
2 of 46584-S0100 = $1.76 each
1 of 46512-H0101 = $0.91 each (manual transmission only)
If the cruise control on your 1987 300ZX does not work, you might have an issue with the cruise control fuse or wiring. You could also have a problem with the switch that turns the cruise control on and off.
Vacuum lines, clutch switches, ...
The ECU has a cruise control speed limiter that will not allow the cruise control to be set after that speed has been exceeded.
cruise control does not work on 98 astro van
Cruise will NOT work if the speedometer has a problem
the crusie control band is probly broken
cruise control does not work when headlights are on
Have you tried pressing the cruise control button on the dash?
If you have a manual transmission the stop button on the clutch switch may have broken apart, replace the stop button to fix the cruise control. You can get one at any Nissan Dealership.
My 08 GMC Sierra has Active Fuel Management, and it does work while using cruise control.
You probably need to install a new cruise control component.
Does the "cruise" light come on?