Engine Overheating

On my [i:878c521d56]1991 Acura Legend[/i:878c521d56] engine starts to overheating after I ride it for awhile. I changed thermostat, temp computer sensor, radiator. The only way I prevent engine from total overheating is by turning A/C on. This way my fans (under hood) turn on and let coolent circulate better. I thought it's headgasket so I added speacial healing solution to fix any leaks. I even tried to take out thermostat and it still overheats but not that much. Some say it's problem somewhere in computer/electricity. Others say it's headgasket. Now I'm thinking of making custom button for radiator fans. What should I do?[/B]