93 1/2 ton with Intermit. fuel pump

My 93 1/2 ton 2wd Chevy/GMC 4.3 V6 auto pick up, has some kind of electrical problem. It will start up and drive for 5-30 min. at a time but will eventually stall from the fuel pump (2 years old) not getting power. For some reason the brake lights come on and won't go off at the same time but not always. When I disconnect the battery for 30 seconds and reconnect the brake lights go off and the fuel pump works again until the same thing happens again. Also just recently the brake light on the dash came on but the brakes seem to be fine. Can anyone help? Are the brakes and the fuel pump on the same circuit?

Thanks,
Carmen

The fuel pump is on it's own fuse. Sounds like you have a short somewhere.
The brake light you see on the dash is the Anti-lock brake light telling you that you have a problem with the Anti-lock brake system.