Which headlight wire for high/low beam

[doug.nichols]

There must be an obvious answer to this question because no one else seems to have asked it. I just purchased a new light harness and am connecting it to new headlight sockets (two light type, no cowl lights). The standard Model a wiring diagram shows the green wire and red wire going to the main headlight bulb but I cannot find any indication of which wire is for high beam. For that matter, the wires coming out of the main light socket do not have a high beam indication either. This is starting to feel like one of those " I am overthinking this" situations. Can someone please educate me?

Thanks

[Y-Blockhead]

Green & Black High Beam, Red & Black Low beam, Yellow & Black Parking. Low Beam filament should be on top.

This is a very good wiring diagram

[Bob C]

The insulator has the color marked on it.

[JoeCB]

Without straying too far from the OP... and thanks "Y" for the filament orientation info. I just purchased and installed 32 - 32 cp bulbs from Snyder. The bulbs I replaced had two identical filaments, kinda' "V" shaped. The new bulbs have one "V" shaped and one transverse linear filament, like one would see in a stop light bulb. So, is this a correct bulb? and if so which filament would be "low" and which "high" ?
Joe B

[Badpuppy]

Originally Posted by JoeCB

Without straying too far from the OP... and thanks "Y" for the filament orientation info. I just purchased and installed 32 - 32 cp bulbs from Snyder. The bulbs I replaced had two identical filaments, kinda' "V" shaped. The new bulbs have one "V" shaped and one transverse linear filament, like one would see in a stop light bulb. So, is this a correct bulb? and if so which filament would be "low" and which "high" ?
Joe B

32/32 should have identical filaments. You can flip it over if one filament burns out. Longer filament length = higher resistance, lower CP. Does it have a number on it?

Also be sure the wiring is correct at the switch end, off-park-bright-dim-off. Seems out of order, but it isn't. Some miscreant wired mine wrong then soldered the tabs in. So I have to reverse them at the bucket.

[doug.nichols]

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So, when the light switch is moved to the high beam position, does it just activate the second of the two filaments in the bulb, rather then there being a designated low beam filament and high beam filament?

[JoeCB]

Originally Posted by doug.nichols

So, when the light switch is moved to the high beam position, does it just activate the second of the two filaments in the bulb, rather then there being a designated low beam filament and high beam filament?

If this question is meant for me … the "high" switch position lights both filaments.

Joe B

[Y-Blockhead]

Originally Posted by JoeCB

If this question is meant for me … the "high" switch position lights both filaments.

Joe B

No, this is not true. Both filament do not light in the high beam position. In the high position, the brighter filament should light. The brighter (high beam filament) should be positioned as the lower filament in the reflector.

[Bob C]

There is a low beam and high beam filament. The low beam filament goes
on top above the center line of the reflector.

[Bob C]

Here's how high and low beam work.

[redmodelt]

"32/32 should have identical filaments. You can flip it over if one filament burns out. Longer filament length = higher resistance, lower CP. Does it have a number on it?"


The one filament is off center and is the low beam and which goes on top. Both filaments in a 32/32 sould both have the same resistance. If the low filament burned out and you flipped the bulb, you would still be lighting the high filament that would be in the center and would not give you a low beam. You have to take into account the shape of the reflector and position of the filament in the bulb.

[Badpuppy]

Originally Posted by redmodelt

The one filament is off center and is the low beam and which goes on top. Both filaments in a 32/32 sould both have the same resistance. If the low filament burned out and you flipped the bulb, you would still be lighting the high filament that would be in the center and would not give you a low beam. You have to take into account the shape of the reflector and position of the filament in the bulb.

Hm - I admit I haven't seen one in the flesh, I assumed the filaments were equidistant from the centerline, for Twolite reflectors. Bulbs for H-type have the bright filament centered, with the dim above and forward, as you describe.

Socket sleeves in H reflectors are centered; Twolite reflectors' sleeves are elevated 1/16", which allows equidistant filaments. Easier to make the bulbs, i guess.

Recheck beam height if you swap between the two.