Brake light problem on 2000 Sonoma

My friend bought a very low mile 2000 Sonoma, we just realized he had no brake lights, all 3 are out, (high mount and both sides) we have put new bulbs in, checked fuse and all are good,wiring intact as well, fuse port for stoplamps is energized when pedal applied. Dealer suggested that the signal/wiper control/ cruise assembly might be a fault,
anyone had anything similar?

I can't say about a 2000, but with my 85 there are 2 switches under the dash that control the brake lights and the cruise control. They are side by side and the 1 operating the cruise has 2 vaccum hoses going to it

well, it was the switch that mounts on the top of the brake pedal.
it has a plastic contact point that had worn down and was no longer closing
the contacts to complete the brake circuit.
$15 dollars and a trip to GM and all good.