In the picture above of steering column appears what looks like a rivet. It is really a tamper proof screw that when drilled out allows whole switch and interlock to be removed. There is a write up in the archives?
Did this years ago and replaced complete unit. In my case the tumbler went bad.
Glenn
Richard;
Great pictures and a clear description of the switch.
dsd David Divins is the OP and had the hot switch. From your description and photos my switch has the phenolic base.
Thanks for your post, Joel.
Mine is now a screw. I’d need to drop the column to get clearance to remove the steering lock.
Thanks!
Just a quick update from the Dr:
Looks like the switch is burned out. But it appears that it was the wrong switch for the car. Apparently, someone hacked together an older style switch and jammed it in there. So that’s being fixed.
The real issue, as suggested above, was the AC. It was wired direct to the ignition. This is being resolved properly via a relay.
Hope to have her home soon 
1 Like
Mine is a '68 which does not have the locking mechanism but had similar heating issues of the keyed switch. The problem is Ohms Law gets in the way. The electrical power dissipated in a component is I^2*R. There’s a lot amps flowing through that switch which will create heat if a small series resistance develops in the contacts. I added a remote relay for the radiator fans which were the main source of current draw which solved the issue for me.
The fact that it loose implies that the contacts might also be worn. That’s when it really starts heating up. When you get around to replacing it, the best way to prevent it from happening again is a breakaway key fob so that you have no weight at all on the ignition key.
Car was repaired promptly. We put a 40amp relay in for the AC and a new ignition switch.
Thanks for all the support!
Erica is right… that is important on these old cars with this type ignition key. I have seen multiple failures caused by a big dangly batch of keys.
LLoyd
Wherever space and time interact, there is information, and wherever information can be ordered into knowledge, and knowledge can be applied, there is intelligence.
Pavel Mirsky, mid 21st Century Russian General
Interesting, I just have the Ignition, door, and glovebox on my keychain.
Just being old will also do the trick, every time the contacts open the contacts tend to arc, many years of that they carbon up, and it is just a matter of time before they overheat.
Level 2 preventative care would be a simple relay on the ignition circuit. I have yet to do this, but it’s about 146b on the to do list.
I set up a relay and fuse for each position/function of the ignition switch, which eliminates any high amperage through the switch. It works beautifully and you can hear the reassuring clicks as you start the car.