Sounds like a weak turn signal flasher
It turns out the problem was that a couple of bulbs on the left side were burned out (front left turn signal, one of the rear turn signal/brake light bulbs.) After replacing the rear bulbs, the signal would work, albeit slowly. Once I pulled the front left turn bulb (with the intent of replacing it the next day), the turn signal light went steady-on regardless even without moving the signal indicator arm. That problem also went away when the remaining bad bulb was replaced.
Gross domestic product
A fast paced dashboard indicator light usually means that there is a failed bulb somewhere on that circuit. Check all the bulbs including side markers and mirror lights if equipped on that circuit (left/right).
Segregation was such a strong custom that it was basically the unwritten law of the south. Other northern states slowly moved away after the 1890's. But, segreagation was never an actual law in states.
The turn signal flasher is about to die. Buy a new one ... they are cheap, usually under $10
slowly
Cities grew slowly because their way of life was so unfamiliar to 19th century Americans. They were well established in a rural economy.
You know a turn signal has burnt out when the light on the dash flashes very slowly, or just stays on until you cancel the signal. I don't think there is any way to know that it is about to burn out.
Halatosis
Turn the key on but do not start the truck then slowly press the gas pedal to the floor 3 times
Generally, a change in turn signal blink rate is an indication of a burned out bulb. Depending on the manufacturer's design, some circuits will speed up, and some will slow down, when the current load is reduced.
I have a '94 Grand Prix GTP and the turn signal works intermittently; when activating the turn indicator lever, it either stays illuminated (not blinking) or it blinks extremely slowly. I stopped by the Pontiac dealer today and asked the parts desk dude if there were available replacement turn signal relays I could order. He said there were no relays for this model and that I'd have to buy the turn signal "switch", which was approximately $150. He showed me an exploded illustration of the steering column and there were two different switch versions; one with radio controls in the steering wheel and one without. To replace this switch, the steering wheel will have to be removed, and if you have airbags like I do, you'll need to take it to a mechanic to get past the airbag/steering wheel. Just checked online and they sell either version of the turn signal switch for $56.90: http://www.1aauto.com/1A/turn-signal-lever/Pontiac/GrandPrix/1AZTS00011/345740