Cruise control won't engage

I have an 03 tacoma with cruise control, which has been working fine until i took it in for its 50,000 mile check up. The dealer insisted that it was the switch so they replaced that for $216 and turns out it wasn't the switch and they still charged me. And then they said it was the ecm and that it would have to replace but i didn't, so i left it at that. But the odd thing is that the cruise control does not blink when you turn it on, however it does not engage at all when you press on the switch. Any solutions?