Wiring Sealed Beam Headlights

[Hudsn47]

Hello, I'm about to wire a friends 1929 Tudor headlights which are 3 prong sealed beams. It has the stock light switch with 3 wires going to each headlight. As I understand the sealed beams have prongs for high, low and ground. The 3 wires coming from the light switch are high, low and parking. What is the correct way to wire the sealed beam headlights in the absence of a parking light? Do the sealed beams get grounded somewhere? Thanks.

[Tom Wesenberg]

You'll have to see which sealed beam terminal is the common one (connected to both filaments at one end) and ground that to the headlamp bucket. Then see which filament is on top, and this will be the low beam.

Some people have had trouble with some repro contact plates, which are made from plastic, not bakelite. The plastic can get hot from the added current draw of sealed beams, and melt.

It's much easier to view which filament is lit if you use a welding helmet for viewing.

[luckyal]

Great advice from Tom. My set came with plastic and the second time out they melted smoked. I finished the drive home with cowl lights.
Al

[Hudsn47]

So guessing the best way to wire the sealed beams would be with a separate switch?

[MikeK]

Originally Posted by Hudsn47

So guessing the best way to wire the sealed beams would be with a separate switch?

Not necessarily. Start by seeing what kind of contact disc you have. Some of the switch discs are thermoplastic and will melt as Tom W said. Many, including two complete harnesses I purchased with a pre-wired Signal Stat 900, have thermoset plastic and will not melt. Pop the bail and remove the bottom half of the switch. If a soldering iron does not want to melt it, you're OK. If it does, you can avoid an ugly extra switch inside your car by using relays for the high and low.

[Willie Krash]

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I'm with Mike,

If your gonna use the the ford style headlight switch I'd use a headlight relay and take that load off the switch. Bosch or Beuller (BU-5083-0000) 1 inch square, very small.

[Hudsn47]

Thanks, I'm familiar with the headlight relays and taking the load off the switch and that's a great idea. We'll be getting after the wiring this weekend so will let you know. Right now the pigtails are just hanging out of the buckets and I just got the switch and harness re-installed. Next is hooking up the tail and stop lights and headlights. The owner had started a restoration and got interupted by life events 30 years ago. The wiring was one of many things that needed finished. Really appreciate the support from this forum as I help him realize his dream of getting his Model A back on the road.

[marc hildebrant]

Do the sealed beam highlights draw more power than the 6 volt halogen bulbs ?

Also, would the sealed beam headlights be a better choice since previous tests have shown that the halogen bulbs are not as "focused" as the original design ?

Marc

[Mike V. Florida]

Originally Posted by marc hildebrant

Do the sealed beam highlights draw more power than the 6 volt halogen bulbs ?

Also, would the sealed beam headlights be a better choice since previous tests have shown that the halogen bulbs are not as "focused" as the original design ?

Marc

The "best" lights are restored originals but that is not what the question asked. Sealed beam lights need an additional ground (I would remove on of the rivits in the bucket and replace it with the screw that looks like a rivit). The sealed beams are smaller and requires an adapter to set in place.

There are many A owners with each type of lights and power source. Like oil, it is a matter of opinion of what works and what does not.

http://www.snydersantiqueauto.com/3821 headlight shell screws

http://www.snydersantiqueauto.com/3802 sealed beam adapter

[MikeK]

Originally Posted by marc hildebrant

Do the sealed beam highlights draw more power than the 6 volt halogen bulbs ?

Also, would the sealed beam headlights be a better choice since previous tests have shown that the halogen bulbs are not as "focused" as the original design ?

Marc

Which 6V sealed beams and which 6V halogens? Most of the 7" standard 6V sealed beams draw 28-36 watts on low, 32-40 watts on high. It varied by manufacturer and specific model number. A pair would draw ~9-12 amps on low, ~11-13 amps on high.

The several available 6V halogens range from about 32low/36high watts to over 60/64, so a pair could draw the same or considerably more. Of course, more light out in the wrong direction is useless. Sort of like someone holding a flashlight for you and pointing it in the wrong place. Brighter isn't much help.

A sealed beam will never deliver a parallel focused beam to either a '28 vertical ribbed or a later twolite lens. Internally, the sealed beam delivers a focused beam to its own lens, but that lens refracts the light in different directions to form a driving beam pattern. Sending an already re-directed beam through the model A lens which further refracts the light down and sideways results in a terrible pattern with way too much side spread.