I have been reading on past threads about issues with the orientation of the headlamp bulb filaments being wrong. The lighting on the coupe and fordor has always been very poor so I took a look at the filament orientation. Sure enough the filaments are vertical rather than horizontal. I though the problem may be caused by the sockets being made wrong so I dug out a good original one and tried the same type of bulb in it. When the socket is held with the tab to the side, as it is when in the lamp bucket, the filaments are still vertical. Obviously the problem is with the bulbs and not the sockets. Does anybody know where I can get correctly orientated bulbs? I am thinking about drilling a new hole and cutting a slot in the headlamp bucket tube and rotating the socket 90 degrees, but I would much rather get the right bulb rather than modifying the original parts.
I ordered some sockets from a vendor and "worked" on them so that my original 1915 angled connectors would point down instead of out to the side. Go for it!
I use old stock bulbs, but have never paid any attention to the filaments. I have 21-3 cp bulbs in my '25, and that is what Ford used, except I think his were 21-2 cp.
If the filament shape is simply a straight line filament between 2 tie bars then your bulb is not going to focus regardless of whether the filament is vertical or horizontal. Correct bulbs that will focus have the filament in the shape of an indian teepee.
John, one filament is a teepee and the other is straight.
I don't drive my T at night so it is not a problem for me but for those of you who do drive at night, consider this... Would it be feasible to re-orient the bulb filaments by carefully re-cutting the two L shaped socket grooves precisely 90 degrees from their current position so that when the socket is inserted in the new grooves the filaments will be positioned vertically? Jim Patrick
Jim, doing that may cause the socket and bulb contacts to not line up any more.
Guys, can you please tell me how the orientation of the filament, vertical versus horizontal, has any appreciable affect on lighting? Yes, I understand focal points and all that stuff but, unless you have a true point source of light, in a more accurate mounting than a mass produced piece if tin, I think you're chasing your tail.
The filament that John describes will be better, but still, it's a Model T Ford headlamp, not a piece of lab equipment.
Here is an earlier thread on headlight bulbs with some diagrams:
So, are proper bulbs available?
My experience is that the bulb orientation makes a huge difference in the light pattern.I have an early '26 with the fender mounted headlights which sets the filaments at approx. 45 deg., compounding the problem, which James Golden was referring to in the linked thread. I've turned them every which way without satisfaction.
Yes and no. But you have to look for them, places like 2nd hand stores, ebay, flea markets, yard sales etc. Even back in the day bulbs came in different configurations. Some had the filaments parallel and some had them 90 deg. to the contacts on the base. The Mazda number is 1114 it has the filaments 90 deg. to the contacts on the base. That's the old number don't have any way to cross reference to more modern number.