no power to heater control

so might be a bit long.               the other day out about in the car put car in to park then it would not come out of park.so i was told by take the battery lead off for a little while and it might reset it self no it did not and that was by someone who used to be a car mechanic. And when i called the recovery driver he told me  there is a little button you can push to move it in drive and i found that and got the car home. And when i went to look at it next day could not get the heater control unit to work so checked the fuses and was all OK so i changed the unit and still does not work and changed the relay as well nothing. I can hear the unit behind it making noise. I have changed the cruise control on brake pedal and i have no brake lights as well. so going to get one of them switch. An