Blinking ac control head light

I've had a continuous problem all summer with my ac. I push in the ac button on low and it stays on for about 15 seconds and then starts flashing. I took it to a repair shop and owner said low refrigerant. Did a service and light continues to flash. Took it to the dealer and they said to replace all of the ac system. Took it back to a repair facility, refrigerant level was good. Troubleshooting followed. Owner said control head is bad, replaced but not the problem. Owner said the ac amplifier is in need of replacement. Seem to be getting closer to solving the problem. It's hot out here in Ca right now. Yesterday I used my truck and it seems that the blinking light stays off longer on low , maybe 30 seconds then it flashes. I went shopping and it was very hot when I got back into my truck, I thought I would start my truck with the ac on high position. Guess what?? ac stayed on for about 30 minutes until I got home. Any one have any ideas ?? AC goes off on Low position, and stays on in High position. Is this a miracle or should I look furtheer?

 

Read this: https://www.tacomaworld.com/threads/a-c-light-blinking-troubleshooting-guide.440200/

Good reading for your problem.