2001, 208k miles.
What's the easiest method of troubleshooting?
Do I start by replacing the relay? Cruise control was intermittent at times, but now it's completely dead.
I don't think any of the rubber tubes have fallen off.
Take the hose that runs across he bulkhead to the vacuum valve on the brake pedal off the Tee by the actuator and try blowing down it. If you can blow down it, that is your problem, it will have perished and will be leaking where it goes through the bulkhead.
Just because you don't think any hoses have actually come off, it's good odds the ends have split are good.
Particularly the black tube from the brake pedal to the tee.
Check the end at the tee for splitting.
Cut off 25mm and try it again.