While replacing the defunct terminal block, I'm also getting rid of the tacky plastic-covered wiring and plastic insulators. That means new horn wires. Are they supposed to come through the firewall by way of the big hole, like all the others? Do the two little holes to the left belong there? If so, what are they for?
My '22 Coupe has the horn wires running through the big hole in a wood fire wall. It doesn't mean I have them right but that's the way they were when I got it. I know it not the Touring you ask about but I think when our cars are close in years Henry didn't change much in production methods.
Those two holes,and the one below coil box bolt(it has a wire running through it),don't belong there.
I don't know what Ford did but just this weekend I ran my horn wires though that big hole with the loom coming from the switch panel. I also got a rubber grommet to help prevent chaffing the wires.
Grommets are available at the big box home centers. I bought mine at Menards. They came 3 in a package for less than 2 bucks.
The horn wires should go thru the smaller holes, not thru the big loom hole.
1923 low hood metal firewall
By 1924 the horn wires were routed thru only one of the small holes, ref. Para. 125 (b) in Ford Service, p.37 and photo at Fig. 99, p.36.
Had too much wine for dinner, the wires in the first photo are in the coil box mount holes!
Here is a better example:
'25 high hood firewall above
'23 low hood firewall below
Dan,excuse me,but you or your "apple pie " have those wires going through the mounting holes for the coil box bolts.
Note that the pictures above from the Service Manual are for the high hood cars.
I thought it would be nice to install a rubber grommet in the large hole, which measures 1". At the local "hardware store" the young lady who was busily scrambling merchandise on the shelves interrupted herself to search unsuccessfully for rubber grommets. At the Orscheln store, after I explained what a grommet is, the "associate" dutifully searched all the places I had searched, then found a place I had missed. Voila! There were grommets! Unfortunately none were 1". The sizes skipped from 7/8" to 1.25". My next stop was Fasten-some. They don't stock grommets in the store, but they can order one if nobody else in town has it. Next I went to the electrical supply house that supplies all the local electrical contractors. Zippo. So I wasted almost an hour of my day to come up with no grommet. This is why I loathe shopping.
C'mon Steve... take the 1.250 and cut it to fit. The wires will keep it in place and if the cut is at the bottom the judges will never see it. Oh shoot... its not even supposed to be there! Disqualified. Mine has the edge rolled over towards the inside making a radiussed edge. 1923 high radiator firewall/hoodformer. Pound a tapered pin in and roll your own edge. troop
I'm not sure if the '23s ever left the factory with metal firewalls. I know they were available as a replacement unit thereafter. Perhaps some of the late low radiator cars had them, but to answer you question, I think the horn wires should go through the big hole. That hole is rolled over some to prevent the loom wires from being damaged, so if you have a new loom, and horn wires, you shouldn't have a problem. The late firewall that Dan posted does have the separate hole for the horn wires.
References on the low steel firewall are pretty scarce. I'm not sure I have ever seen a picture of an original from back in the day. Looking over every book I have and pictures of cars here on the forum I came up with my own best guess. Partly is was just a matter of seeing what worked and looked right with the repop harness. Here is a pic of my solution:
There are a couple of unused holes in my firewall and I'm not even sure they are original. Here is a pic is one of them that might have been used for the horn wires:
Jeff, I found a pic of the firewall just out of the blast cabinet:
It looks like the holes you were asking about are there on my firewall as well.
Yep, that's the same firewall I have. I'm going with those who say the two little holes to the left of the big one are for the horn wires. When I got the car it had both the (plastic-covered!) horn wires through the bottom small hole.
I'll skip the grommet and go stock.
I don't know what the small hole below the bottom coil box mounting hole is, but I'm using it for my bike speedometer wire.
I'll take a picture when I get it all back together.
Pretty sure the little single hole below the coil box lower hole is for the switch to horn wire on the low firewall. Then the other one, the switch to terminal wire routes from the big hole.
Here is schematic showing a high firewall, note that both horn wires, the switch to terminal, and the switch to horn, go into the smaller hole.
I don't mean to hijack the thread, but I have a closely related question. In all the diagrams I've seen, both for later "electric" cars and for those without the starter/generator/battery, the horn switch has two wires, one from the power source to the switch and one from the switch to the horn. My early TT has a '15/'16 steering column (which I believe to be original), the one with the horn button fastened to it with two screws tapped into the top of the column. On the bottom side of the column is the wire tube. As far as I can tell, it's not possible to get two wires, at least not two like the "horn" wires I purchased, to go through the tube. Am I missing something?
I mounted a manual "plunger" style horn to get by, but would prefer to put an electric horn in the 'ol truck using the original switch.
First off - the "battery" horn did not show up until first quarter of 1922. Prior to that the "electric" horn being referred to was magneto powered and that began in 1915. From 1915 till sometime in 1917 there was the pushbutton on the column as you describe. The horn that goes with that is the EARLY magneto horn and neither of its connections was a ground. Those early mag horns have 2 connections on them for power and as I said - neither is grounded inside the horn. The wiring was from the magneto terminal on the coil box to one of the horn connections and then from the other horn connection to the steering column mounted button via a single wire and that wire was grounded to the column by that horn button. That was the way it got its power so you are correct there was only 1 wire in that wiring tube on your vehicle. This was used until the intro of the combination horn/light button/switch which was sometime in 1917 but essentially is a 1918 feature. I have not researched the actual intro dates of the combo switch but it was NOT on a 1916 and WAS on a 1918 so far as I know. On those the magneto power went up the steering column and was connected via the combo pushbutton to a HORN WIRE which ran down the column to the later version magneto horn which had one of its terminals grounded at the horn. The other ungrounded terminal got the horn wire from the column mounted combo switch. Some of the left over 2 connection magneto horns were still used in production later and they simply removed the outer fiber washer from one of the 2 power connections to cause that connection to then be grounded by the terminal nut with no other wire connected. Simple stuff really.
Thanks for the answer, John! I get it, which electrically speaking is an achievement for me.
Now I have another question: The truck (and cars of that vintage) has a wood firewall. That would, I think, necessitate the ground connection being dependent on the steering linkage, the carburetor linkage, and/or the spark advance, right? It just seems like not the best way to ground something, but if that's how it was designed, I guess it worked OK.
Time flies when you're swimming against a tide of incompetence. I knew I had several wiring diagrams to go by, so I didn't think of taking a close-up picture before removing the wiring. The catch is that the geniuses who produced these harnesses decided to get "creative" with the colors of the wires they used.
The diagram says the green generator wire is supposed to be yellow & black. Note the tacky modern plastic insulator. I'm replacing those with black rubber. Is that exactly "correct"? Dunno, don't care. It's not a show car.
The red magneto wire is easy to spot, but how about the others? Which one is the green tail light wire?
Which of the wires hanging down is "green"?
This MAG wire is supposed to be blue & yellow. Ha! Needless to say, I'll be checking every circuit with a meter.
I had the same problem when I removed the connections to the terminal block. The not-that-old repop harness had faded even though it was never exposed to sun. The car has a hood but the colors all looked the same so I marked each one with masking tape ahead of time. On reassembly it was just a matter of putting all the wires mark 1 on the number one terminal and so on. I'm afraid you are going to have to go over each one with a meter to figure out which is which. Happily, Model Ts do not hat so many wires that even simple persons such as myself can't manage that.
Where did you find the black insulated fork connectors? Restoration Supply has the "flag" style but not the direct ones needed for Model T applications.
I was going to just post a picture of the finished terminal block, but after seeing Paul's question I took these shots. Everything except the cloth covered wire is from the local hardware store.
So here's the way it is now. You can see the horn wire from #1 going into the upper little hole, and the wire from the button to the horn coming out of the lower little hole.
Thanks Steve, I didn't know the plastic insulators would come off of those modern looking forks. I'll have to give that a try.