am I right in assuming the brake on/off switch is bad???

'88 trans am. blinkers work. 3rd brake light works, running lights work. however, when I hit the brakes only the CHMSL illuminates.

if I'm wrong, where do I snoop next?

 

IIRC, there are often at least two switches for the brakes lights, and at least one of them should have separate pairs of contacts for the regular brake lights and either the ECM/Cruise Control circuit or the CHIT lamp. The circuit for the CHIT lamp is from a light blue wire on the pedal switch directly back to the lamp contacts on the hatch, and to the lamp. That is apparently working properly.

The Trans Am is different from Sport Coupes and Formies in that the T/A shares the turn and brake lamp functions. The circuit for the regular stop lamps is through another light blue wire at the brake pedal switch, then routing through the Turn/Hazard signal switch in the steering colum, and finally back to the lamps. For the lamps to function, the Hazard signal switch N.C. contacts must be fully closed.

If the turn signals are working, the wiring from the Turn/Hazard switch back to the lamps is intact. Since you indicated that the "blinkers work" I presume the rear turn signals are funtioning normally. However, for the STOP lamp circuit to work, both the turn signal contacts AND the hazard contacts must be closed. If the hazard switch contacts are intermittent, the regular stop lamps may not work. You might try to exercise the hazard switch several times to wipe the contacts clean and see if the brake lights then operate.


This is the circuit:

 

i'm going to have to go out and look some more.

I replaced the brake switch, and verified it works to that point. also the turn sigs work fine, hopefully it's just the contacts or something.

but it looks like I'm finding some creative wiring all over this car.

now all a sudden the alternator stopped working and the TA barely limped me to my parents home.

i have no clue whats up, because the alternator is BRAND NEW.

i love thirdgens, but I hate finding someone elses hack job. If my GTO had t-tops, I'd be one happy camper.