My Volvo S80 has about 114,000 miles on the clock. Recently the cruise control started dropping out for no apparent reason. The "Cruise" indicator light comes on and stays on whenever the system is turned on. There are no error messages. Sometimes it will activate if I hit the Set button again, sometimes if I turn the system off and back on it will work again, it's sort of hit or miss. There is only one switch on the brake pedal. I know this operates the brake lights, does it also have contacts for the cruise circuit?