Model A Light Switch

K

kiddcom

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I have a 1928 Model A and we have performed a little maintenance over the week-end and ran into a little reassembly question. Our wiring diagrams seems to show that the Light Switch should be a 4 position switch (low beam, high beam, parking, off). Unless the switch is toast, there seems to be only 3 positions. When the lights were reassembled and the wiring color codes checked and rechecked, we ONLY have low beam in 1 position, off, parking. Now the question. What is the correct function of the Light Switch (by position)? We have a replacement wiring harness, but the color codes seem to match original.
 
It should be high beam 4 oclock, low beam 5 oclock, off at 6 oclock and parking at 7oclock. At least on mine it is which is a 29.
Pete
 
You have the 2nd generation light switch; it works just like the very early light switch except it has a bail to hold the lower cover.

The correct headlight bulbs were 21/ 3 Candle power; you do not have a high beam, that is why only 3 positions: park to the left, off in the center, driving light to the right.

Your headlights, if you have the correct harness, should only have two wires to each headlight. The headlight conduits and their connectors should be smaller, and also the exit holes in the rediator shell should all be the same size as the holn wire hole.

Sorry, do not have any pictures to post.

Ron
 
If your wiring diagram shows the 4 position switch,thats the diagram for 29-31.The 28s use a different switch & a different bakelite contact disc on the light harness.
 
If your new harnes came with the contact plate already attached it will be for the 4 position lights, 1929-31 Twolite system. You will ned to unsolder your original contact plate from the old harness and use it with the new wires. The 1928-early 29 contact plate has 4 brass contacts located at 12 o'clock, 4, 6, and 8 o'clock. The twolite system has 3 groups of 3 contacts equally spaced around the plate.
 
HeadlightSwitch.jpg


Flutedswitch-1.jpg


Here you can see how the switches and contact plates differ from the fluted headlights and the Twolite lamps, with the top picture being the later style Twolite system. The top right cover is the longer cover used in 1930-1. You can see two styles of contact plates used with the Twolite switches, with the one of the right with 9 brass contacts being the more common one by far.

BTW, for those wondering how the Caswell copy cad plating system looks, these are parts I plated using my Caswell kit.
 
We have a 1928 Model A Sport Coupe. I just redid the light and horn switch and it was working great. High beam at 4 oclock, lo beam at 5 oclock, off at 6 oclock, parking lights at 7 oclock. Horn worked fine. It has a bail holding the switch to the steering column. When you switch the lights on and off several times the bail comes loose, the switch slides down and the switch nor horn work. Anyone know how to get the bail to stay without using a zip tie. Henry Ford didn't have zip ties and I would prefer to not use one either.
 
indyward said:
We have a 1928 Model A Sport Coupe. I just redid the light and horn switch and it was working great. High beam at 4 oclock, lo beam at 5 oclock, off at 6 oclock, parking lights at 7 oclock. Horn worked fine. It has a bail holding the switch to the steering column. When you switch the lights on and off several times the bail comes loose, the switch slides down and the switch nor horn work. Anyone know how to get the bail to stay without using a zip tie. Henry Ford didn't have zip ties and I would prefer to not use one either.
Click to expand...

Two lengths of the bail were used, so if you have the short cover, be sure to use the short bail.
If it's still too loose, then bend the wire more to shorten it.
 
Reviving an old post here. I need to solder the old 4 contact plate to a new harness, but the old wiring was already cut off the contact plate to compare to. Does anyone have a diagram of the original wiring positions for the 4 contact plate? Thanks.
 
Tom Wesenberg said:
HeadlightSwitch.jpg


Flutedswitch-1.jpg


Here you can see how the switches and contact plates differ from the fluted headlights and the Twolite lamps, with the top picture being the later style Twolite system. The top right cover is the longer cover used in 1930-1. You can see two styles of contact plates used with the Twolite switches, with the one of the right with 9 brass contacts being the more common one by far.

BTW, for those wondering how the Caswell copy cad plating system looks, these are parts I plated using my Caswell kit.
Click to expand...

what exactly is holding the 3-bump plate, and the spring behind it, to the rest of the upper cover?
 
My concern is that the “old” 4 contact plate is different from the 9 contact plate and without a pin out diagram, I cannot solder the new harness to the old contact plate.
 
I found it. For those needing the actual pinouts, the center contact is the horn (blue and yellow), 12 o’clock is battery (yellow) and stop (green), 4 o’clock is bright (Black and green) 6 o’clock is tail (black), 7 o’clock is dim (black and red). Hope this helps someone.
 

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Well, it’s been years since I posted about my headlamp switch plate and I am going to need to replace the bak-o-lite contact plate in my 1 light, 3 position switch. Again, the switch is the 4 contact 1st gen. Where might I source the contact plate? I have looked everywhere.
 
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