Had a strange thing happen over the weekend. Both headlights and the tail light burned out all at the same time. What would cause something like that to happen??? The wiring is only 2 yrs old and has been working fine. Did my switch do something it should not of??

Larry Holderman
Warsaw, IN

One scenario: Generator lost connection to battery and overcharged. Hopefully, this is not it, as it could easily have fried your generator.

It would be the voltage. How is your generator set? A generator can put out 8 volts. Using the mag for power source? The mag can put out way over 12 volts. It has to be a power surge of some type.

Larry,

I'm just assuming that you are running DC headlamps and when you say blown you mean blown and not just 'won't light'. Won't light can be a loose wire at the terminal block or at the switch. Blown is filaments gone or dangling loose in the bulb.

If all 3 went at the same time and it was not a bone jarring pot hole that just fractured the filaments in vibration, then pretty darn quick you should check your wiring or your generator for something not quite right would be my guess.

Assuming you are set up for 6 volt and they were nominal 6 volt lamps, seeing 8 volts reduces lamp life on average to only 4% of rated life, getting to 10 volt source is virtually a same day failure.

There is no way the battery itself can make more voltage than what it is rated for, so if it wasn't a mechanical induced failure, my guess is that somehow, something changed voltage, or you somehow managed to charge your lamp circuit with mag voltage.

I had the same thing happen. In my case, it was a loose terminal on the back of the ammeter that I believe shorted to ground.

Loose connections was the first thing I looked at and everything was tight and not touching anything. I am running 6 volts with the normal 6 volt bulbs from the suppliers. The generator wire seems fine. All of the wiring was new 2 yrs ago and the gen. has been charging at about 7-8 amps on the gauge. I am thinking more like the switch did something. I replaced all of the bulbs and it is charging fine and everything works. Gremlins have moved into my T...

The problem is probably a loose terminal at the battery. If the battery experiences a momentary disconnected while driving like hitting a bump in the road, the voltage will spike up knocking out the bulbs (All of them). The battery is what keeps the voltage at a fixed level, not the generator. Any connection that disconnects the battery from the charging system can do the same thing.
I am surprised that more of you have not seen this happen on a generator system.

This is common with this type of electrical system. The connection at the battery terminal gets corroded, or if you are using a cutoff switch in the battery cable, the switch has corroded. Or the wire at the terminal block or starter switch is loose. Wherever the cause the problem is between the ammeter and the battery. The There is a loose or corroded connection, so the charge is not going into the battery, but directly into the lights. The battery itself in this system is the voltage regulator. When the battery is out of the system, the full power of the generator goes into the lights and the voltage is too high so they blow out.

If all the generator's output goes to the bulbs only, due to a bad connection, usually on the ammeter, the generator can put out 30 to 36 volts, but only for a few minutes, or just long enough to fry all the bulbs. That happened to me with a Model A about ten times before I found the loose ammeter connection. It is real exciting on a dark night to have all the lights go out at 50 mph.

2 times the man asked whether his "switch" was the problem. My emphatic answer is that if it is not the problem now it most certainly will be the problem at a future date but I suspect it is in fact your problem now. Toss the switch - they cause trouble and do not save your system from anything. I would recommend you install one main fuse of 25 amps in the heavy yellow wire that comes off the battery side of the starter switch. That will protect your low voltage wiring from any short in the system beyond the fuse and it will blow regardless of whether you see the problem that it sees or not. The switch only allows you to disconnect the battery when the car is stopped and you see smoke. By that time most of the damage is done. Toss the switch - install a fuse then you have real protection and less trouble.

Assuming he means a battery disconnect switch, you are right John. If he means his ignition switch or headlight switch, then I'm not so sure. Definitely sounds like a poor connection between the generator cut out and the battery. I'm bettin' somewhere in that circuit, there is an intermittent 'open'.