Headlight intensity

spinelll

spinelll

Senior Member
1930 Roadster, 6 volts. The driver side headlight is cleary brighter than the passenger side. Wiring? Grounding?
 
Is one on high while the other is on low? Switch the hi/lo beam switch and see if the dim side suddenly is the bright side. If thats the case take out the bulb and turn it 180 degrees in the socket.
 
The A bulbs fit either way, pins are equalil spaced, if you have 32-50 cp bulbs one could be in 180 degrees from the other---but then the brighter headlight would switch sides when going from high to low. --if the wires in the headlight connecter are switched (look a filament in bulb--the same one should light on each side)
A grounding problem can be checked with a length of wire ---perhaps to a headnut---and touch the focus screw--that is the ground for the headlight socket to shell
 
Also make sure you don't have high beam and low beam wires crossed on that side. First headlight switch position to the right (5 p.m.) is high beams, second position (4 p.m.) to the right is low.
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The above is not correct. Page 34 of a 1930 copyright Ford Model "A" Instruction Book states: "Turning handle first position to right from the "off" position gives a downward tilting beam for city driving. Turning handle to second position provides a beam which gives exceptionally brilliant road illumination for country driving."

Headlight bulbs have staggered pins on the side of the base. They will only go in one way.
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This incorrect infromation has already been corrected. Pins are NOT staggered on headlight bulbs for Model A Fords.

There is a wealth of great information here on Ford Barn. You just have to be careful on what you believe to be factual. Guess some folks are just trying to help but don't have the correct information.
 
The original type bulbs, 21-21 CP and 32-32 CP, both filaments look, and are in fact identical. One filament ( hi-beam) is on-center, the other (lo-beam) if off-set: this is what "shifts" the beam when switching from one beam to the other.

The modern 50/32 bulbs have two different filaments: the "pointy-one" is usually the lower wattage, the one that looks like a regular "straight" #1154 or 1129 stop/tail-light wall is the higher-wattage filament.

As Kurt mentioned, the pins are not "indexed".

As for different intensities, try swapping the bulbs from side to side... if the lower intensity travels with the bulb, then it's a bulb issue. If the lower intensity stays-put, that sounds like the issues is grounding / connections in that particular headlamp bucket. Would suggest making that observation with the lenses off the headlights, looking at the bulb itself.

Once you've determined that you've got the same type bulb on both sides, and the connections & grounding are good, you can put the lenses back on and go about focusing and aiming the headlamp assemblies.
 
If you run 21/21 or 32/32 cp bulbs, how do you get high and low beams out of that? The 32/50 I can understand,just turn bulb 180,to get the correct alingment.
 
29restorod said:
If you run 21/21 or 32/32 cp bulbs, how do you get high and low beams out of that? The 32/50 I can understand,just turn bulb 180,to get the correct alingment.
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There are two factors that play into this. First (and simplest) is that fact that the upper filament reflects downward and the lower filament reflects upward so you end up with an upper and lower beam directionally. Second (and not known by most) is Ford's actual placement of the filaments. The socket retainer in the rear of the reflector is NOT on center. It is located 1/16" above center. This places the lower (high beam) filament exactly in the center or focal point of the parabola when properly focused. This provides the brightest and most even distribution of light. This then places the upper (low beam) filament 1/8" above the reflectors focal point which reduces the intensity of the light as it also directs it downward.

It's important to note that this applies to "Twolight" headlamps only. The non-script Ford "H" headlamps used until about April 1929 had only one driving beam in the headlamp bulb. The driving filament was placed in the very center of the bulb and the reflector socket retainer was placed precisely on the center line of the reflector.
 
On the subject of headlights, I am trying to straighten out the wiring someone messed up on a Model "A" I just got, is the low beam wire suppose to stay hot with the high beams on, or is it suppose to go off when the high beams are turned on, because I have power to the low beam wire when the low beams are on, but when I turn on the high beams, I lose power to the low beam wire, is this normal? And, yes, I do have power to the high beam wire when I turn on the high beams. Thanks in advance. Keith
 
the low and hi beams operate seperately. when low beans are on the hi beams are off and when hi beams are on the low beams are off.
Hope this helps.
 
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