Alternator replacement wire

[Cowhorns]

Hi everyone.
Working on my F4 (R2109) I noticed that one of the wires attached to my Marchal alternator was completely stripped of insulation. See photos. I, rather my much more experienced colleague, plan to replace this length of wire. The thing is we dont know what amperage we need. Its the wire that connects to the terminal on the top/RH side. Also be good to know what this wire actually does. Any help appreciated.
Thanks

Peter

 

[angel]

It's the field excitation terminal. No high current there, 1.0 square mm wire should be enough.

 

[Cowhorns]

Great! Thanks for your help.