Burning out headlight bulbs

[Joe/Ct]

I have a '28 roadster with positive ground 6 v battery and a generator. I keep burning out headlight bulbs. I have the generator set for 10 amps with the lights on. Suggestions?

[J Franklin]

First the generator should put out about 0 amps or less with the lights on. Next make sure the light sockets are clean of corrosion and they and battery are securely grounded. Check for loose connections between the generator and the battery. Older bulbs were rated for 6-8 volts and new Chinese bulbs are 6 volt.

[johnbuckley]

poor ground at headlamp fitting is another possiblity.

[updraught]

If you disconnect the battery with the lights on and rev the engine the lights will blow as the power goes straight to the lights, instead of being absorbed into the battery.
So check battery connections.

[Synchro909]

I think Updraught has it right.

[eagle]

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Originally Posted by Joe/Ct

I have a '28 roadster with positive ground 6 v battery and a generator. I keep burning out headlight bulbs. I have the generator set for 10 amps with the lights on. Suggestions?

First make sure you have a 6v battery and not an 8v. Second, if you have a battery disconnect make sure you never disconnect it while engine is running. Third, get yourself a fun projects voltage regulator, battery will last longer, no more messing with the third brush, they are a great addition to an A.

[rotorwrench]

Some reproduction bulbs may not be very resilient to rough roads or common use. The better the condition of the suspension and tires, the better everything will last. Lamps only draw the current they need and shouldn't be affected all that much by generator output. The battery sets the voltage of the output so it shouldn't get high enough to burn the bulbs out if it is the correct voltage. Higher than normal voltage will certainly burn a bulb filament. Higher than normal current will overcharge the battery and overwork the generator. A bad alternator can burn bulbs filaments if the car is converted to alternator and the diode bridge goes out.

A person could try a different brand of bulbs if available.

[Patrick L.]

I agree with most of the responses. A poor connection/ground can cause these generators to run away and produce 30-40v. Also 10 amp charge when running with lights on is a bit too much.

[redmodelt]

With the lights off and an engine speed approx in the range of 20MPH the generator would be set in the 4-6 amps depending on driving conditions. While I would have to do the math, the KR Wilson generator testing and setup stand would be spinning the generator in approx the 900-1000 RPM range for setup. At 10 amps with the lights on is too high esp so if setup at idle speeds. As RPM increase so does output. The cutout is not a limiting device so as long as the points are closed the line voltage is going somewhere, lights battery etc. At 10 amps on a long drive would be good way to overcharge and boil your battery. That is why the output was set depending on the season and how much the cars were driven. Short trips higher base output, longer trips lower output.

While the diode type cutout replacement is not hard to find, the Fun-Project actual regulator has been hit/miss for sometime re availability.

[Tom Endy]

A likely culprit is the battery ground cable where it connects to the frame. It is out of sight and out of mind and under the car where it is exposed to all kind of corrosion. Remove the battery to access it. Remove the bolt, nut, and the cable and wire wheel them. There is a raised boss on the frame where the cable connects. Clean this area thoroughly, remove all rust, paint, crud, and any powder coating. Make sure it is clean bare metal. This should be done every time you replace the battery.

Tom Endy

[Synchro909]

Originally Posted by Tom Endy

A likely culprit is the battery ground cable where it connects to the frame. It is out of sight and out of mind and under the car where it is exposed to all kind of corrosion. Remove the battery to access it. Remove the bolt, nut, and the cable and wire wheel them. There is a raised boss on the frame where the cable connects. Clean this area thoroughly, remove all rust, paint, crud, and any powder coating. Make sure it is clean bare metal. This should be done every time you replace the battery.

Tom Endy

Very good advice but I'd also use some dielectric grease on the connection. It will prevent any further corrosion and help make a good connection.

[IndyA]

Doesn't T.J ( I believe that was the first responder's name?) had a mis print..shouldn't the am meter read "0" when the lights are OFF not on???

[redmodelt]

If you are talking about J Franklin's post; Not sure what you mean by 0 with the lights off? In normal operation with a points type cutout, the meter can drop to 0 or just above at lower road speeds with the lights on and maybe just under when stopped sitting with lights on.

[IndyA]

Remodelt is right... with my former bulbs (i've now switched to LED's) the am meter should show around 10 amps at idle and bulbs off.... with the bulbs on the meter should go down to around 0. The LED's use only about 3 amps but that's not material to this conversation... Apologize for the mistake...

[DHZIEMAN]

Possibly a bad ground someplace!