I had the A/C and blower motor on max output last weekend and for the first time I witnessed smoke form the around the key switch.
The bottom cover was very hot and I sourced it to the the two 12 gauge battery power "feed" wires from the battery to the ignition switch. They have been hot for some time as evidenced from the cracked plactic cover located at the underside of the column.
I installed a relay to power the blower and electric windows as opposed to the key switch.
I hope to test my work by monitoring the temp of the two wires feeding the ignition switch.
GL