My 1915 was originally equipped with a kerosene tail light which I have converted to an 1157 bulb (easily switched back). Hooking up the brake light to a brake switch was no problem but getting the tail light to work with the existing headlight switch is problematic.
1. Hooking the tail light to the low beam wire means the tail light is on only when the low beam is selected, and off when I switch to high beam.
2. Can't hook it to both the high beam wire and the low beam wire because both high beam and low beam headlights would come on together.
3. Could install a separate tail light switch, but where to put it ? How to remember to turn it on when I switch on the headlights ?
4. Could hook the headlight to both high and low beam wires using diodes, but this will drop the voltage to the taillight by 0.7 volts. Enough to significantly reduce the light output.
So, how have others solved this problem ?
On my boat-tail, I just hooked the tail-lamp up to the bright headlamp connection. The dim headlamps aren't really bright enough to be practical for night driving anyway. One thing, though, with the boat-tail, I can just look over my shoulder to see that I have the lights switched to include the tail-lamp. Your car is likely more difficult to see your tail-lamp from the driver's seat.
Drive carefully, and enjoy, W2
Split that black tail lamp wire at the terminal block, like a forked snake tongue, solder another wire to the tail lamp wire so you have two wires.
Put the two wires, one each, to both the hi and low beam. Which ever headlamp lights, the tail lamp will follow.
Dan, both high and low filament will burn that way.
Get two diodes and run one each to the high and low terminal. Attach the other end of both diodes to the tail light.
Forgot to mention: You can use 1N4001 diodes available from Radio Shack if you can find a store that still stocks parts. They're 1Amp and small enough to hide with shrink-tube or solder them in-line.
Oh boy, I'm must be having brain drivel.
Also, pay particular attention to the bar mark on the diodes. Both must be toward the tail light.
Bud, by adding just two diodes to yer diagram, you will have what you require. The diodes prevent the voltage from feeding back into the other headlight wires from whichever one is powered at the moment. The brakelight portion of your tailight might draw near 2 amps depending on which bulb you use, so pick a diode of atleast twice that rating and you'll be good to go.
I had thought about adding diodes ( see #4 in original post) but I am concerned about the voltage drop of about .7 v across each diode. I know it doesn't sound like much, but its that last volt or so that about doubles the light output.
Maybe in the real world it really doesn't matter that much.
Has anyone actually done it ?
Yep, I had a problem with my switch on my 25 touring. Could not get the tail light to work with the head lights. One or the other would not light the tail lights. Added the 2 diodes and the tail light works no matter which headlight setting I use.
I have read that the electric tail light was an accessory and it was wired in series with a dash light similar to the head lights, therefore if the dash light is not on nore is the tail light. The tail light is powered from the dash light that is switched. The dash light is powered from any hot source. The location of the dash light is optional.
The dash light becomes your tattle-tale as to the status of your tail light.
I run the regular 1915 ignition switch below for my 1915:
With the below light switch for my 1915
I have only the head lights and tail light running light wired to that switch mounted on my wood firewall.
I run a separate power line from the battery to the brake light switch to the brake light wire of the tail light.
Very simple wiring.
At least with Dan's method you would get brighter lights since you would have at least 60 CP (both filaments burning) or if you have a 30/50 CP bulb you would have 80 CP ok so now are we getting to the point of blinding oncoming drivers?
What switch are you using? If it's non-Ford switch, consider using a double pole - double throw (DPDT) switch which is in effect what Ford used originally.
I thought of another way you can install a taillight switch and be able to use the tail light when you are using either high or low beam lights. Put the new switch in series with the headlight switch between the battery and the headlight switch. Then run the taillight wire directly from the new switch. Then use the new switch to turn on or off the lights and use the original switch to switch from low to high beams. You could still turn off the headlights with the original switch. Whenever you park you should check to be sure the taillight is off. I assume you do that anyway to be sure the brake light switch is not stuck which can sometimes happen if the pedal does not come all the way back. Put the new switch in any inconspicuous location.
I wired my '16 with mag headlights and 12V LED tail and stop. I added a second switch, so that during the day I can run the Tail light separately from the headlights. If I forgot to turn the tail light off, the power draw is so low, it will take several days/weeks to drain the battery.
If you are concerned about turning it off put a pressure switch under your seat
After reading some of the previous posts, I have a question. Where is the terminal block on a 1915?
Another question: When did Fords come equipped with and wired for high and low beams? Hint: Not 1915.
Good question...I forget...can't get back to it until spring - it's "hibernating". Do you see one here?
Fords came equipped with the wiring for high/low beam in 1919 when the starter and battery was introduced.
They didn't (come with terminal strips, that is).
But, by the time you add an electric brake light, brake switch, taillight, magneto charger, klaxon, fuse and a battery, point to point wiring just isn't fun to do anymore (or to try to diagnose when there's a problem).
A terminal strip was the way to go, original or not. I did make it out of wood though.
OMG! Plastic wire?
I have not done it yet but I think it would be neat to make a single wire brake/tail light by using a few diodes in series to take advantage of the voltage drop for the tail light. Then bypass the diodes with the wire from the brake switch to apply full voltage to the bulb. That way you only have the single wire running to the back of the car and have both a tail and brake light. I tried it on the work bench and it worked.
(Message edited by paulmikeska on December 10, 2014)
Great idea ! I am in the process of building a tail/brake light from some super bright LED's I bought. That would be an easy way to provide for both levels of brightness.
Not only plastic wire but all recycled. There's wires from an old extension cord, computer power supplies, and from and old boat trailer ! Hey, wire is getting expensive ! ;o)
(Message edited by schuh on December 10, 2014)
If you added the diode stack to both Hi and Low head light terminals, then tied them together with the single wire going to the tail/stop light, and intersected both after the diodes with the brake light switch feed I think it would solve the original problem and the tail light would only be on when the headlights were on. Food for thought.
(Message edited by paulmikeska on December 10, 2014)
HMM.... The more I think about this there are a couple of ways to accomplish this. Not sure how to diagram them on this computer so that they could be posted.
You can easily use two 6 volt relays instead of diodes if you're concerned about the voltage drop. The coil of one is connected to the low beam terminal, the coil of the other is connected to the high beam. The contacts are both hooked up to the battery, so when either relay is activated, the light will turn on. I can come up with a diagram if you'd like!
Paul, if you have a scanner or copier/scanner you can just draw your diagrams on paper and scan them.
I do have a copier/scanner/printer but have only ever used it as a printer and have never scanned or copied anything. LOL. Maybe this is a teachable moment... Stay tuned!
Well foo! My wireless printer needs a cable to the USB to scan. Thanks Epson. I will need to find a cable tomorrow or... Still stay tuned but be patient.
Paul -- If you are successful at scanning your drawing, you probably will need to re-size it to get under the 195kb limit to post it here on the Forum. Anyway that's my experience with my scanner; just didn't want you to think it will be too easy.
Funny you should mention a diagram. I did the diagram below last night using your idea of the one wire tail light. It essentially follows you description in your last post.
I show an LED tail light but of course it would work as well with a standard filament bulb,
The series of diodes at the top of the diagram are to adjust the brightness of the tail light. Each diode only drops the voltage by 0.7 V and the diodes shown at the switch may not be enough to dim the rear light enough to act as a tail light. The number of diodes to achieve the desired brightness would be found by experimentation.
BTW I bought ten 1000V 10 amp diodes of amazon recently for $2.06 . So they don't have to be expensive. eBay is another place to find them.
That is exactly what I was thinking and is a much better diagram than mine.
Thanks for the idea Paul.
BTW here are the diodes I bought $2.11 for 10 and free shipping! Can't beat that!
http://www.amazon.com/SODIAL-Molded-Plastic-Rectifier-Diodes/dp/B00JFONY7I/ref=s r_1_3?s=electronics&ie=UTF8&qid=1418346593&sr=1-3&keywords=diodes&pebp=141834660 9246