[Gearhead999]

Since the brake light and the turnsignals are the same filiment in the bulb the problems are connected.

See if the flasher is good, just change it they are very cheap. Check all the grounds in the trunk and out front where the front parking lamps are. I think you might have a turnsignal switch bad. Pretty common problem.

Now the dim headlamps...is another story. Is the generator/alternator putting out proper voltage?? If it is then you're loosing it as it goes to the headlamps. See what voltage you have a the headlamp bulb plug. Let us know.