No power output from my vector 1000w inverter.

Question

The green light is on, the red light flashes. Every time the red light flashes the fan starts and the power level lights flash and my driving lights dim all at the same time. When I initially installed the inverter it worked fine. After I tested it with a 500w light I unplugged the light and left the inverter on for approx. 10 mins. When I returned, the symptoms had begun. Any ideas? Thanks