Toyota Repair: toyota pickup electrical problem, toyota 4x4 pickup, toyota pickup

Question
When driving my 1989 toyota 4x4 pickup,the brake and battery warning lights come on and stay on until i shut it off.There is nthing wrong with my brakes or charging system.Also when I turn on my stereo there is a loud and constant buzzing noise so that I have to turn it off.I think something is is grounding that shouldn't be.If so how do I go about finding it? PS I have read alot of your posts and you are the best. Thanks for your time.

Answer
The brake and battery lights do come on because there is a problem with the charging system and the problem is that the alternator is not charging the battery, this is the only reason for these lights to come on at the same time, replace the alternator to solve the problem.