Radiator Fan Themostatic Switch Cable Toasted

You might see if Rhode Island wiring sells what you are looking for. They sell all kinds of automotive restoration wire. You might just see what all of that wiring harness costs from the wrecking yards (TRutlads, Eurospares, or Ferrparts?)

The Smoking Tire video about his 308 has a section where his mechanic mentions that new wire harnesses are available and not terribly expensive, both parts of which surprised me.

Routing that one wire will not be easy, but it is probably relatively short. I'm sure it goes in the big bundle that exits the front bulkhead in front of the fuse blocks.

 

Did you find a reason for why it is toast? The current in that Yellow-Green wire should be very low (like something less than 0.5A), and it is an unfused circuit. The only way I can dream up how that could happen is some sort of unusual short inside the R.H. Relay. Was that R.H. Relay and Fan working OK? Or were both the R.H. and L.H. Fans not working? At a minimum, you should remove the R.H. Relay and give it a gentle shake to listen if anything is rattling around inside, and I'd replace it anyway.

 

Yes, it was. Relays with the diode between terminals 85 and 86, as shown in that diagram on the outer case, require that terminal 86 be the positive and terminal 85 be the negative for energizing the coil -- if reversed (as it is on your model), it looks like a dead short. You could use that type of relay if you move the GV (yellow-green) wire, the negative, to terminal 85, and the GN (yellow-black) wire, the positive, to terminal 86 in the relay socket (Ferrari wasn't careful with the polarity because the stock relay doesn't have a diode). I'm surprised that you didn't fry the ignition switch.