1988 Mazda 626 Lights intesity fades and increases

After having the transmission of the car fixed by my favorite mecanic I noticed that the when the car is on the road the intensity of all the lights (headlights, dashboard) and even the speed of the A/C blower will increase then decrease. This cycle goes on and on. The harness that controls the A/C blower (the one inside the car, under the dashboard) also went bad and was replaced with a used one. I also removed the old car alarm thinking that may have be the cause but it was still there. After a couple of weaks the high beam side of the headlights will burn, then about a week after that the low beams will also burn out. So far I have replaced the headlights three times. Any help will be deeply appreciated.

V/R,

- Raul