12 volt prefocus bulbs

[Harry Moon]

When I first got my C15a Wire 5 I had a heck of a time getting the headlights to work
All the circuits worked and I tested the2331 bulbs but no way would they work when installed. I put sealed beams in instead for the winter and back to the bridge plate and blackout light in summer.
I then, (I'm slow on some things) discovered that the contact points are out 90 degrees. So I had some success heating up the flange and rotating it 90 degrees but that was of limited success.
recently in researching a guy who will make halogen bulbs to fit these things I found out that the 12 volt bulbs are 90 degrees to the 6 volt bulbs. trouble is nobody could find me any at parts stores. By chance I found out that those cheap Chinese scooters that are imported use a 12 volt prefocus bulb of the correct orientation. The part # is 6245Y. I bought 2 on eBay and they snapped in place and work.
Looking through the parts manuals I think my truck probably was originally a 12 volt and not a 6 volt, lots of different headlight bucket assembly's.
Mine was built July 44 and the headlight bucket was the original ones with the wire wrapped loom
All I did was change the Voltage regulator to 12 volt and the bulbs. Now I think I might dig up the original gas gauge that never seemed to work on 6 volt and see if it works properly now. any body else ever notice the difference in the orientation of the contact points in their headlight sockets?

[Phil Waterman]

Hi Harry

Just this afternoon I replaced the 6 volt Halogen bulbs with some of the old prefocus blubs which I had done just what you describe of re-soldering the base and rotating them. Some of the bulbs also have the ring the wrong distance to the base which is corrected the same way.

But back to the 6 volt halogen bulbs, while they are a lot brighter than a standard Prefocus bulb and with a good reflector nearly as bright as a seal beam they have in my experience a short lived. I drive with my headlights on all the time (no mater what I'm driving) and the 6 volt halogens last about half as long as a 6 volt seal beam. Put the halogen in two trucks at the same time and the low beams of both failed this spring.

Photos below are some test that I did when I first installed the Halogen bulbs. 1st picture Halogen Left standard 2331 Prefocus right both LOW beam. 2nd is Halogen Left standard 2331 Prefocus right both HI. Type of mount is the 3rd picture

Halogen is brighter and tighter but shorter lived.

Cheers Phil

PS- All three of my trucks have 6 volt systems which have not given me any reason to change over to 12 volt having said that, all three trucks carry 12volt batteries as well to power radios and accessories . When I put the 261 engine in my C60S I was concerned about starting so I installed a marine battery switch will allow me to shift just the starter over to the 12 volt in an emergency to start. Think I've used the 12 volt for starting maybe twice.

[Harry Moon]

It could be Phil that your trucks light fixtures were on a 12 volt truck, if original maybe your truck(s) was originally 12 volt? Try those 12 volt bulbs, no re soldering of 2331's

[Phil Waterman]

Hi Harry

I got my blackout headlights years ago, don't even remember where. They are visual match to those shown on the 1945 production HUPs and to what is shown in the late Driver Handbooks.

As to bulb numbers I will have to look to see if I am using the same number your are. Which could explain the difference in the base.

Cheers Phil

[Lynn Eades]

So back then, to change over from left hand drive to right hand drive, you would have installed a left dipping or right dipping bulb.
Is this anything to do with the problem?

[motto]

I've always believed that l/h or r/h dipping is determined by the lens pattern and that the bulb remains the same as does the reflector.

Somebody will know for sure.

David

[Lynn Eades]

Sure the lenses can change,as well, but that's just about diffusion of light.
The placement of the filaments in (these "Pre- focussed" bulbs, we are talking about) dictates where the light is projected,(e.g.,on low beam, to the left or right) by the parabolic curve of the reflector, and hence the dipping left or right.

What I am asking Phill and Harry, Is, have the bulbs or bulb holders for left dipping and right dipping lights been mixed up, because the placement of the disc soldered on the bulb will be the difference between dip to left, or dip to right.

The lenses used to be the same, when the glass was a separate part from the reflector.
The introduction of the semi sealed and sealed beams, necessitated a specific LHD or RHD application. the bulb is a std bulb (same for lhd or rhd), but the bulb holder part of the assembly is rotated to hold the bulb at a different angle.
e.g. Std. American war time sealed beams are no good on Australian or New Zealand roads
Here are some other nearly relevant ramblings.
If you look at carriers for instance there was no adjustment at all for where the lights pointed.
With earlier cars, the person fitting the bulb had to adjust the position of the bulb, by moving it in or out of the holder, to get the best light pattern, from the reflector. This is why they came up with "Pre-focused" bulbs.

[Phil Waterman]

Hi All

First concerning the issue of left or right dipping or which side of the road are you driving on. Logic says that the bulbs should be different, which will take some research are seal beam head lights numbers for North America different from the UK and Australia?

The observation from my testing with different pre-focused blubs is that they don't seem to dip down to either side they are much more up or down. With the prefocused Halogen bulbs I was using 6v 35/35w P15d-30 APF Base #170-756H from Classic and Vintage Bulbs, Blackwood South Australia http://www.classicandvintagebulbs.com/ I suspect that if there was any down and to the side for low beam that they would have been down and to the left. But from my test picture the change in pattern from hi to low is minimal. The photos in first post came out wrong way around. This picture is the high beam for alignment purposes the orange line on the floor is running just down the right side tires. Halogen left regular prefocus right, as you can tell from the hood in the foreground this was taken sitting in the drivers seat.




The photo below was actually of the low beam alignment.



Now to Harry observation about what number bulb I was using and 6v or 12v. Harry you were right on the money the bulbs that were in the black out units when I got the units were 2326 12-16Volts and the ones I was resoldering base on are 2331 6volt.

If I were driving my trucks a lot at night I would go back to the Halogen even with the shorter life they are brighter and whiter light.

Cheers Phil

[Lynn Eades]

New Zealand and Australia drive on the left, like the U.K. (and Japan) Yes the sealed beams are different (as are semi sealed beams) Say if you were converting a WWII Jeep or Dodge to Halogen H4, we would have to buy left dipping semi sealed beams.(you dont haveto ask for them of course,the electrical shop would only stock the correct ones for that particular country) Without looking at one, I don't recall how they are marked.

[Lynn Eades]

Phill, I have found a listing for 12 volt 1044, for use in USA,and 6 volt one, a 2330, also for the USA. There is a BA15D base, and a BA 15S base. Don't yet know the difference.