1966 Thunderbird had for 15 years. The Car starts un fine and when I even slight touch the breaks it dies. So When I Press the break, just even a slight tap car stalls. When it first happen I heard a rear buzz sound int the back of the car and the shut down. But started up again. This seems seems to come and go. The idle seems fine. I'm wondering if its electrical? And how to trouble shoot for it. The car has been sitting for a while. Don't want to have it stalling on me. But cant get to shop to have them look at it if it keeps stalling.

A bit more information would help. With the transmission in "park" and parking brake on, can you raise the rpm's to approx. 1200-1500 rpm and then while holding a steady engine speed, step on the brake pedal. Does the engine die immediately? Can you release the pedal quickly and keep the engine running?

Disconnect the connector on the brake light switch and then see what happens. If it doesn't stall you have a problem in the break light circuit. If it still stalls disconnect the vacuum hose at the power booster and plug it. If it doesn't stall the problem is in the power booster. If it still stalls check the wiring under the dash near the brake pedal linkage. You may have a wire that is being shorted out when the brake pedal is depressed. Good luck and let us know what you find out.