Esprit S1 - Ignition Switch Mount

[jtmco]

It is known that there were two ignition switches (at least?) used on the Esprit S1.  This is reported on several posts including:

S1 Ignition Switch Hot

S1 Project car - part 2

The photo below shows my original switch (left) and the replacement sold by SJ.

The diameter of the replacement switch is larger and so it will not fit into the hole for the smaller switch (on my car).

There are reports of the smaller switch matching a TR6, but that appears to be the larger switch.  There are other reports of it matching an MGB, but the match is not that close.  I have a Moss Motors (USA) distribution center about 45 minutes from my house.  I visited and they were unable to match the smaller switch.  I looked at other distributors (late 1970's Mini Coopers,....) with no luck.

So, I decided to make my own holder so I could mount the larger switch in my car.  This required two components:

First, there is a small "key" or "pin" that fits in the switch.  This connects the rod from the ignition key into the switch.

Since the larger switch does not go down into the hole, this pin needs to be extended. Using some 1/4" x 5/16" steel bar stock and some flat stock, I made the following piece (welding and grinding):

The original pin fits in the bottom of this exten:

This extension piece fits in the bottom of the switch and extends the pin.

Then I made a holder out of Delrin.  I bought some tubing that was 1.5" ID and 2" OD.  This is ALMOST big enough for the switch to fit inside.  Using a knife and a grinding wheel on a drill, I opened it up (just one end) so the switch would fit inside.

I also flattened one side on a grinding wheel so it would fit against the steering column.  I added a sheet metal screw as a set screw to help keep it from rotating.  I drilled two holes to match the column (same as the "ears" on my original switch).

I also bought a piece of 2" Delrin rod and a 1 1/4" spade bit (wood drill bit) and made a cap to hold the switch in the tube.

The original switch was held in with two short screws that seemed to be 4-24 sheet metal screws.  I bought some new screws (and washers) with the same thread that were 1 1/2" long.

I re-used the connector from the old switch (the wires were the same colors so I just switched them out)

The switch is now installed:

Mechanically, it seems to work just great!  You can feel the switch move to each notch through the key.  I have not yet reconnected the battery (need to check a few things first), but I don't think there will be any issues from my new attachment. 

Hopefully this will help others who cannot find the original switch and don't want to try to find a replacement column mount.