Cruise control "Set" not working. Blower 1 and 3 position broken

I have a Jeep Liberty Sport 03 4 door with 44,000 miles on it. Several thousand miles ago I noticed that the cruise control “set” and accelerate wasn’t working. The on-off switch works but the rest of the cruise isn’t working. I don’t know if it is related, but the 1 and 3 positions for the blower (Heat and A/C) also are not working. The 2 and 4 positions do work. Haven’t noticed problems with other systems except the engine light which seems to be related to the gas cap (see other post). The dealer looked at the cruise control briefly on a prior visit and said it might be related to some vacuum mechanism, although they did not fix it. Was wondering if it is something I might be able to fix myself.

The vacuum thing or the link to the throttle could be disconnected. On the other side, the engine computer/control module could be having problems. Then there’s everything in between. So, if the cruise control is mechanically hooked up to the throttle, you may not be able to fix it yourself.