I've heard that if you have an automatic light switch sut-off switch and are having problem with your headlights flashing like a police car, it was caused by the cars computer.
That can happen when there is a bad ground to one of the lights.
On a 1999 GEO Tracker, a bad fuse can cause the headlights and dash lights to blink. A bad voltage regulator or alternator can also cause lights to blink and flicker.
If the lights flicker when the vehicle is running, the alternator is on it's way out.
If the lights blink fast on either side of the car then this means you either have non-factory bulbs in the car or you need to replace your blinkers because one of your lights is out.
Loose battery or alterator connections
bad headlight switch.
If it is anything like my '88, it is probably a relay. If you have stock fog lights, try turning them off and see if this helps. On mine, if I turn the fog lights off when the headlights start to blink it fixes the problem...untill i turn the fog lights back on that is. there was a recall to correct this-contact your dealer-they repaired mine for free because of the recall.
Blinking lights on dash and exterior lights may indicate a bad ground wire or a faulty headlight switch. Both would cause those problems.
sounds like a bad day and night sensor or bad wiring
If you mean the headlight switch, pulling it out once turns on the dash lights and turns off the daytime running lights, pulling it again turns on the headlights.
The bulb may be blown or weak,also check the flasher.
loose bulbs