lvmyvt76

my headlights have started going off and on , replaced headlight switch, don't drive it much at night.. Switch have an internal limit going off an don??/


also, whats the best of replacing dash-lights with something brighter and being able to dim them???? don't think you can dime leds??

Denpo

Sounds like a bad contact, there is not protection beyond the fuse, and once it's blown, it's blown. edit: I was wrong

Maybe something get hot in the headlight switch.
A good measure is to install relay near the headlight and only carry thru the headlight swith the current necessary to close the relay. That removes a major source of fire hazard.

Led can be dimmed, but it needs PWM rather than lower voltage, thus the dimmer resistance in the headlight switch will produce a weird result, namely a color shift followed but a sudden switch off.
Another problem is that most PWM led dimmer work by switching the negative side, the line between the bulb and the ground. Electrically speaking switching the positive side, the line between the + and the bulb don't make much sense, leads to overheating.
Positive side switching is still possible if you roll your own circuit. I have something like that in my project list, a device that reads the current headligth switch resistance, and create from that a positive switched PWM to dim the dash led.
The other way around is to rewire all you bulb so that the ground is carried by a wire rather that the dash chassis, and put a negative side switcher dimmer on this line.

65GGvert

There is no fuse for the headlights. There's a circuit breaker built into the headlight switch. If it gets weak, or the light circuit draws too much current it will open and when it cools down (a few seconds) will close until it gets hot again. If it does it more often or faster on bright than dim, the breaker is most likely weak. If you have a bad contact at or in the headlight dimmer switch, it will also go off and on, but not in a rythmic rate like the breaker. You need to specify the year of car for more dimmer info. You have to change the headlight switch if the breaker is bad. Remember it may be doing what it's supposed to because you are drawing too much current in that circuit.