A lot of good replies here. I absolutely MUST point out that the brake switch input is a safety that overrides all others for the design of the cruise control system. If a mechanic has diagnosed something wrong with the brake switch, I would go ahead and replace that AFTER I eliminated the battery issue. Going through the manual to troubleshoot the control wiring (at the BCM leading to the switch assembly at the column) would be hard enough for someone but if this wiring is an 'intermittent' then good luck in having it fail while your testing these various wires 'continuity'. The cruise control wiring bundle is wired/designed to operate the system but the brake cutoff circuit is a primary safety system above the protocol of the operation of the system. On a second note, I have seen more and more suspicious activity around high EMI locations. Our cars are being deluged with systems easily interfere with by high EMR in locations that transmit these signals. If a shielding discrepancy is causing this, there will be no amount of parts thrown at the car that will eliminate it. IMHO.