Why do your headlights blink on and off?

Answer 1

ok as fars as the blinking on and off, there is a relay usally around the computer control box. Inside that box is a set of fuses and relays. Any lights that are on autos and have switches need relays ,if not for relays the switches would burn up the relay controls the temp.i don't know if your having the same problem as me? after about 20 minutes of the lights being on they start to shut on and off continously, sometimes they completely turn off. I found that the problem is not the bulbs. I tested the current without the headlights using a voltmeter and found that the current actually cuts off.

havent figured it out, im not sure if its a short circuit.

Headlights "Cutting Out"There could be several reasons depending on how old/new your vehicle is.

For example, if your vehicle has a security system that is malfunctioning that could cause the headlights to flash.

On "older" vehicles the most common cause is a short circuit in the headlight wiring system combined with the protective action of the automatically resetting circuit breaker(s) for the headlight circuit.

IF the headlights go out because the fuse "permanently" "blows" while driving at night, it creates a very dangerous situation, for example if you're driving on a dark, moonless night out on the highway in darkness.

To counteract for that many manufacturers put in automatically self-resetting circuit breakers in instead of permanently blowing fuses. With the circuit breakers, upon tripping, almost immediately or within a few seconds, reset, turning the lights back on so you can avoid driving off the road.

IF your car has this system, the cutting out and on of the headlights indicates that there is a short circuit in the headlight wiring system. The "recycling" of the breaker is almost always the result of a short circuit condition in the wiring of the circuit in which the breaker is installed. See additional answer below regarding fuses that blow on replacement, or circuit breakers which repeatedly trip.

Fuses That "Blow" Repeatedly

Fuses [and Circuit Breakers] are safety devices designed and installed in electrical circuits TO PROTECT the conductors [wires] from short circuits and overload conditions which can cause extreme overheating that can result in damage to the insulation and the conductors. And worse the possibility of a FIRE which could destroy the vehicle, house, or other structure in which the circuit is located.

When a fuse [and replacement fuses or Circuit Breakers] "blow," especially if it happens repeatedly, is an indication of an UNSAFE CONDITION in that circuit, usually a short.

The proper "fix" is for a qualified technician, who knows what he/she is doing, to troubleshoot the circuit, find and identify the defect, and make proper repair [s], BEFORE replacing the fuse again [with the properly sized fuse or circuit breaker].

Some ignorant few will suggest installing a larger fuse or breaker to solve the problem, BUT that will only amplify the problem, not solve it. Do not follow "bad" advice and install a larger fuse in a misguided attempt to correct the problem. To install a larger fuse would almost guarantee damage to the wiring and an electrical system fire.