90' 240sx battery light and brake light problem.

[keepitmovin]

Ok heres the deal. A couple weeks ago out of no where my battery light goes on. The brake then goes on and off (and i notice more so when i hold the brakes). While all this is going on i hear a buzzing sound from underneath the dash. Now i have check my alternator and its running like a champ. I've adjusted the belt several times (alternator). Im not too good with electrical any advice would be appreciated. In addition, this problem comes off on and off very random. Its been 3 days since it has happen, and when it does its usually on 30min+ trips. Thanks in advance guys..I really dont want to take it in, i cant afford to ..

[NISTECH]

I dont think you had your altenator checked properly. Did you have it tested? It sounds like altenator to me or bad wiring to it. poor ground or connection to the altenator.

[keepitmovin]

Yea I took off the alternator and had it tested at kragen, Test shows 14 volts. Thanks for the help im starting to think its a poor ground/connection somewhere. More clues I just remembered:

I have driven the car for a good 25 mintues when this problem happen. If it was a bad alternator would my car have had enough juice to make it? I have had this problem for a good 3 weeks, i would figure my alternator would of dumped on me by now?

I remember when at idle the "buzzing sound" seems to get louder and as i rev up my car it quiets down.

When i rev my engine i hear a sound comming from the engine like a belt is on to tight. But when the problem stops everything sounds the same w/o me adjusting anything.

Thanks again for the help.

[NISTECH]

if the diode tree is getting hot it could be going open which turns on your lights. The audible sound of the altenator is another good indication something is wrong in it. This may be a wiring issue but all signs point to your altenator being the problem.