Is there a source for magneto headlight bulbs? Are any of you using magneto headlights? If so, what are you using for bulbs?
The headlights on Karen's '18 Touring have been disconnected. No wires going to them. Being the hardheaded semi-purist that I am, I am kicking around the idea of going back with magneto headlights, but I don't see the bulbs in Lang's catalog. Of course, if they are not available, the decision will be easy.
My '17 has its original magneto bulbs. They work pretty well at cruising speed, not so well at idle.
I bought a half dozen magneto bulbs at Chikasha from Bill Barth a couple years ago for $5 each.
The 1143 (12.5 volt 1.98 amp) or 1195 (12.5 volt 3 amp) both available from www.bulbtown.com for less than $2 each should work if wired in series as came from the factory.
No, scratch that - both those bulbs are single-pin contacts and you need double pins with the socket isolated from the filament.
I'll try again.....Sorry about that!
Good Morning Hal,
I use #1142 bulbs. They are 12 volt, double contact, single filament. They are reasonably bright yet I've been told that there is a somewhat brighter bulb available. Sadly, I don't remember the number. This #1142 bulb has some RV applications and should not be too hard to source nor too expensive. Magneto powered lamps are interesting to watch at a slow idle, they almost pulse or flicker. Have fun but be safe; when you shift from low into high there are a few moments of low RPM hence low voltage resulting in dim bulbs untill the RPMs pick up again.
Good luck with your project, Bill
The 1144 bulb (12.8 volt/ 2 amp / 21 candlepower / double contacts) also at bulbtown, $2.25 each.
The 2 pin "floating filament" version of the 1195 is the 1196 bulb. Some have used that 1196 directly off the magneto but it is a pretty heavy load and at midrange RPM - not too brite. Better have your front seat passenger equipped with a flashlight for when you sit still idling ha ha.
The typical 1915/1916 T used 2 of the 9V magneto bulbs wired in series and they quickly do burn out if you increase the RPM beyond mid range. Ford never solved that one even though he was convinced it was because the bulbs were of poor quality - he was wrong. He went so far as to design the filament himself and force the vendors to use his design which they happily did - no improvement in the problem. Tungsten just does not like widely varying voltage and short life is what happens when you exceed the design voltage by even small amounts.
For 1917 and beyond - Ford no longer ran the magneto "raw" directly to the bulbs but used a dimmer coil in series which offered then a varying AC resistance to hold the bulb current more or less constant. That worked rather well. A 1918 would have had a firewall mounted dimmer coil that was placed in series with the bulbs.
Thanks guys! I think I might try it, for a while anyway.
John, what would this dimmer coil have looked like? Which side of the firewall? This car has a firewall mounted push-pull (Off-on, respectively) switch that I assume is original? At least I think it is only off and on. I've not noticed anything I would have recognized as a dimmer coil, but then again, I've not been looking either. It may very well still be there. Was it used to dim the lights as in high beam and low beam, or just to somehow flatten out the pulses of the magneto? Would there have only been one brightness setting? Sorry so many questions. I'm kinda "In the dark" on this one.
I thought the dimmer coil was 1919 and later? My '17 roadster is one of the last ones built (June 1917) and it did not have anything different originally from my '15 in terms of wiring or lighting.
What type switch did it have. Is it bright/dim/off or just off/on? I think our's is just off and on, but couldn't swear to it. I will have to go look.
My '17 has its original switch. It is push / pull off and on. Identical to the one in my '15 except the 1917 knob is nickel plated steel.
1915 headlight switch:
1917 headlight switch. Notice how crooked the switch was mounted, this is the original firewall:
The push pull dash mounted light switch was used through the end of the 1917 model year (through July 1917). This is based on real cars (not "put-togethers') with known histories. I also have evidence that the dash mounted switch was used in September 1917, again, based on a real car with known history.
The combination horn button/light switch was introduced in the 1918 model year. This is when the dimmer came into play (if I recall correctly, the light switch has two voltage positions, dim and bright).
My dad's '17 has a "hot" mag and we typically burn out magneto bulbs at higher revs. Mark Cameron gave my dad a cute NOS aftermarket accessory, a small coiled resistor that attaches directly to the light switch. My dad has never installed it on his car but I believe Mark Cameron has one on his '15 and I believe it does keep the bulbs from burning out. Otherwise, there are firewall mounted aftermarket bulb savers (resistor coils in a metal case) that are about the size of a couple of decks of playing cards. Sometimes they can be found at swap meets.
Does the coil in the later Model T's regulate the voltage to the bulbs by the increased impedence at higher RPM's?
Our light switch looks like the one in the photo posted by Royce. I believe ours is an early 1918 model. The date in the floor of the body looked to be Oct or Nov 1917 (Don't recall right now, and it was REALLY hard to read).
The "Poor boy" TT trucks that were sold with out a starter and generator had a coil mounted in the bracket where the amp gauge would be on a normal starter generator version. We had a 1924 TT with that coil, but I never did see the lights work on magneto.
My truck was origionally a Magneto light rheostat system. It was in the dash panel. The previous owner explained to me that in his opinion, they weren't real reliable and converted it. It had been previously converted to an electric start model anyway. I borrowed these pictures from eBay some time ago for future reference.
I am making the new mag bulbs and in the process of the 1915-16 headlamp switch, Bob Bergstadt
For memory we set up our '15 with 12v bulbs in series and though it had a very good magneto, it was exciting to change into top gear and throttle on into the darkness for a while;)
I could never keep a globe in the tail light. It was a period conversion of the original oil light. My solution was a little 3 pin voltage regulator from the local electronics shop. Many cars have one on the back of the instrument cluster. They come in many voltages. I don't even think I used a diode to rectify it... for memory the thing coped with AC.
I do remember that it worked well... the 12 volt tail light was bright enough at idle and didn't blow at speed.
Chime in here Seth;)
The 1142 bulbs work fine and can be bought at any auto parts store. I turn mine on frequently. They are neat looking when they strobe at a low idle.
Restoration Supply Company
has NOS Magneto bulbs in stock. They had a display at the Long Beach T Swapmeet
OOPS!! MY BAD!
At my age I should never operate from memory. I went back and checked the dates and forgot to also mention that my dates are "design change dates" and not on-the-car dates which we have to figure out by ourself. The dimmer coil mounting holes were added to the dash on the engine side on 12/8/1917 and 10 days later moved slightly horizontally towards the center of the car on 12/18/17 probably to gain clearance for installing the top steering column bolt and nut. On 9/23/21 the dimmer coil was moved up higher to a point that made its horizontal center line being about equal with the horizontal center line of the coil box. It also moved further away from the coil box too so it was moved up and over toward the steering column. Probably this was done to save some wire since the new location put it closer to the wiring hole that the wires went through. That wiring hole had been added on 2/5/19. The dimmer coil was used firstly with the "combo" horn/brite/dim light switch as near as I can tell since it ALWAYS had 3 leads on it - magneto, brite tap, dim tap. While the lead lengths changed on the dimmer coil from long to short as it was moved from the firewall to behind the ammeter dummy cover plate, the windings and electrical makeup of the dimmer coil never changed from its beginnings through to the end.
The dash board was drilled for the push-pull light switch up until 10/2/17 so clearly the push pull light switch and RAW magneto voltage was used for the lights from 1915-1917 and into early 1918 at least. Branch assembly also tended to lag behind any new design changes so there is good reason to believe that the dimmer coil and new combo switch may have been even later on cars assembled at branches.
I have the facts here but just mis-reported them because I was operating from memory which clearly is not safe to do any more. I was told recently to make sure to treat my new daughter-in-law nice since she likely would be the one who picks out my nursing home. That may be closer now than I thought.
I got two mag bulbs available from Richmond 2008.