Have posted this same question in the XC70 forum but it was suggested I also posted here as it may get a bigger audience and knowledge base.

Purchased a 2002 XC70, and didn't check on the test drive whether the cruise worked...it doesn't! Yet another lesson to be learnt!!

I have followed the instructions in the handbook down to a tee. The word cruise appears in the appropriate place on the dash when the relevant button is pushed on the steering wheel, but when I go to set it by depressing the + or - button (again located on the steering wheel), nothing happens ie the vehicle doesnt not cruise at the speed set and speed will decrease when I take my foot of the accelerator.

I had the manual out again with the intention of checking fuses, but cant seem to find a fuse for cruise control.

Any suggestions please on the actual problem...is it a fuse ? Or something more sinister?.

Thanks in advance

 

First do this test.
While driving at cruse speeds lift up on the brake pedal with your left foot while engaging the cruse. If that works, there is a bracket that holds the disengage switch for the brake pedal (behind the lower cover) grab on to it and bend it carefully so as to move the switch closer to the pedal arm.

I have encountered this problem in several year volvos

 

Also check vacuum lines under the hood.