2004 RX330 172K miiles
Symptom- internittent cruise control operation when pressing the button in to turn it on

As reading many others having similar symptoms I opted to hit up "Pick-a-Part" and grab a clockspring from a donor car. I installed it but the same symptoms persisted. Today went back to PaP grabbed a cruise control stalk from a donor car and installed it.. .voila solved my problem!

Tool needed ro replace stalk:
- Small pocket knife or small flat head screw driver
- T30 torx driver
- #2 phillips head screwdriver

Process
1 - with pocket knife or small flat screwdriver remove the small 2" trim covers fro the backside of the steering wheel
2 - look to see the torx screws, loosen those and gently pull the airbag towards to DO not tug on it you only want it slightly out of the way behind it you'll see the stalk and the two Phillips head screws holding it.
3 - remove the two screws holding in the stalk, disconnect the white connector at the bottom by depressing the center tab and pulling lightly at the same time
4 - install the new stalk in reverse order - connect white connector, screw in the stalk, reposition the airbag, screw airbag on both sides, replace the trim pieces, done

Total time @15-20 mins, degree of diffficulty is easy just be careful as it is a live airbag
Total cost of the stalk - I got the cruise control stalk AND the motor and assembly from PaP for $10

 

Congratulations on the great diagnosis and repair, and sourcing a recycled part for $10!

 

Great you figured it out. Kinda like window switchs, ect.