Technical Ignition burned wires

[asta69]

I recently purchased a 1982 Fiat Spider 2000. I started to have ignition problems shortly after. I began to trace the issue starting at the ignition switch and didn't have to go very far to find the problem.
Both the black and blue wires connected to the back of the switch showed signs of overheating. The block connector at the end of the ignition switch pigtail had badly melted at the black wire location.
Has anyone else experienced these issues and if so, how did you rectify it?

 

[bugsymike]

If it was just local to the ignition switch I would have said worn switch overheating causing the lucar/spade terminals to lose their grip and get hot.
The ignition switch looks very similar to 1970s Ladas (Fiat 124 copy) we used to sometimes have to replace them when still in the showroom.
However that other wiring plug looks to have been seriously overloaded. Is it possible over the years someone has added non original wires to the circuit, spotlights, stereo etc.?
Can you put an ammeter in between terminal and wire to see how much load is being drawn, maybe turning things on that may be causing the fault, even something like a seized heater fan motor.

 

[asta69]

If it was just local to the ignition switch I would have said worn switch overheating causing the lucar/spade terminals to lose their grip and get hot.
The ignition switch looks very similar to 1970s Ladas (Fiat 124 copy) we used to sometimes have to replace them when still in the showroom.
However that other wiring plug looks to have been seriously overloaded. Is it possible over the years someone has added non original wires to the circuit, spotlights, stereo etc.?
Can you put an ammeter in between terminal and wire to see how much load is being drawn, maybe turning things on that may be causing the fault, even something like a seized heater fan motor.

Thanks for the response.
I did exactly what you suggested last night. The black wire at the pigtail was pulling nearly 13 amps with tcar running. The fan which it turns out had been jerry rigged was pulling almost 12 amps. When i disconnected the fan, the draw at the ignition switch dropped to about 1.5 amps.
In order to keep the fan running and reduce the load on the ignition wires, i wired in a 5 pin relay (12v/30a).
I traced the wire that they had used for the fan power and utilized that as the trigger for the relay. Then ran 10 ga wire for the constant hot and ground.
Once all was said and done, the black ignition wire showed a draw of 1.5 - 2 amps max. A pic of my working notes and installed relay are attached. It needs a little cleaning up but will suffice to keep it running right until i can do a deep dive into the electrical this winter.
Thanks for your help.

 

[asta69]

Now on to figuring out why the dash lights went out....