I had this exact problem with my 1996 rodeo. turns out if you have replaced the brake bulb with a mono-filament bulb this will happen. If you replace the bulb with the correct Dual filament bulb this will fix the problem
My wife has a 2000 L series Saturn, she had a similar problem, the brake lights would work but when you turn on the headlights they would go out... I found this problem when I went to have the required, yearly safety/emissions inspection per our State Law (it failed due to the problem). I checked for recalls for "Saturn" and found that there was a recall for brake light problems, due to the socket which housed the bulb(s) for the brake lights, heating up, and melting the plastic. I then opened the trunk, removed each bulb 1 at a time and inspected the housing(s). Lo and Behold! I discovered a discoloration on 1 of the housings and realized that it had in fact started to melt. I cleaned the housing by scraping away the burn mark on the housing and the housing contacts and tested it... IT WORKED!! I am making an appointment with Saturn ASAP to have this problem fixed... Good luck, I hope this helps, I know that there could be several problems that can cause this other then the 1 that worked for me...
Check the bulbs they are double filamented with smaller being for brake lights
adjusting Isuzu rodeo brakes
remove the 2 screws from the red plastic and gently pry the red cover off.
abs codes are retreved by juming obd2 terminal 4-12 after codes plump brake petal 6 times
Did you check the drive belt to see if it broke?
Possible ground issue at the taillights.
DOT 3
they are not brake lights they are fog lights and they turn on because it is for the car behind to see you
Check the fuse for the headlights. It is probably open.
when all three of those lights turn on that means that your alternator is bad. i just went threw this same problem with my rodeo
How to Install Front Brake Pads Check Related links below.
Fuse for parking lights probably blown.