I will begin by stating that I know less about electrical wiring stuff than most folks so here is a question. I'm putting a T back together and ordered a commutator wiring set and it has 5 wires. There is the red, black, blue and green which I recognize where they are supposed to connect. There is also a black wire with a red thread in it and I have no idea what the ends are supposed to connect to. I have looked at a couple other Model Ts and they both have only 4 wires there??? I would appreciate your comments. Thanks
First, I am assuming you are asking for your 1915 touring "Woodrow." If I'm wrong and you are discussing a different year etc. please let us know.
I believe the 5th wire in the commutator wiring set is for the magneto powered headlamps. Please see the wiring diagrams for 1915-1917 cars at the thread: http://www.mtfca.com/discus/messages/80257/83800.html
Hap l9l5 cut off
Probably the generator wire
Yes, the fifth wire is for the headlamps. Below is a photo of the 1917 Rip Van Winkle touring that has the same push-pull circuit light switch (switch varied with time and manufacturer -- but still on off push pull style and mounted in the same area).
Below is the wiring diagram from the link above.
Disclaimer -- all this assumes you are talking about your 1915.
Hap l9l5 cut off
Hey, thanks a lot for the quick answers. Makes sense that the wire is for the headlights. I'll get back on the project tomorrow. Thanks again for all the help. I'm pretty good when it comes to taking stuff apart but putting it back together is something else.
Note that the original wiring of the headlights on your car puts the bulbs in series. That means if one blows out both go dark. It does have the advantage that the magneto voltage goes through both bulbs so each sees half of the voltage.
I recommend modifying the wiring slightly so that the bulbs are connected in parallel. Basically each bulb has its own ground lead and the hot lead is tapped to go to each bulb. This way, if one bulb blows out the other stays lit. Works real well on battery (6v or 12v), but you now need a way to keep from going over voltage on your bulbs if you use the magneto for them. Any suggestions on bulbs or methods to protect bulbs when powering with a good magneto - 6 to 40 volts AC?
Ford used a dimmer coil to reduce peak electric voltage on the later non electric models c:a 1918-26:
Here seen mounted on the switch panel of a TT truck or hack, but it came mounted on the fire wall on ~1918 cars without any instrument panel. Here's a comprehensive description from John Regan:
"The early version of that dimmer coil mounted to the firewall with wood screws and a couple of spacers. The spacers were in fact the same part number as those used on a standard T coil to mount the point assembly. Later they made a sheet metal bracket thing to mount it to the firewall. Still later the same coil was mounted behind the dummy ammeter cover plate on the very latest T's. The thing is a 3 legged tapped inductor so basically one long winding with an additional connection part way in the middle. The wiring on the combo switch was to bring a wire from the magneto connection (shown in the picture) up the steering column to the combo switch. The horn button connected that magneto wire to the horn wire while the other horn connection was grounded. Additionally that combo switch connected the magneto to one end of the dimmer coil for dim lights with the tap being connected to the magneto for bright lights. The free end of the dimmer coil went to the lights switch via a splice made by a wood screw into the firewall to connect that wire to a wire coming from the light switch. The arrangement inserted some of the winding in the bright position and all of the winding in the dim position and since the inductance of the dimmer coil gave it more AC resistance at higher RPM, the dimmer coil prevented the quick burn out of the headlight bulbs as was the case with the 15/16 setup which didn't use the dimmer coil but used 9V bulbs wired in series which didn't work any better than the 8V battery does when powering 6V bulbs as mentioned in an earlier thread today. That too spelled short bulb life."