Thank you Laurent, I have been to this site but had no luck locating a repair manual diagram. I am trying to find information without a cost. It is even a difficult repair manual to find to download at a cost.
I beg your pardon. I just now found out that there are indeed tungsten-cables.
I found such in the New F1 where it seemingly actuates the viewfinder speed scale. I still haven't found such in the AE-1P. Actually I can't think of a funtion there. But I'll find out...
The tungsten wire connects the ISO resistor to the shutter speed dial which is also a variable resistor.
The setting of the ISO dial changes the position of a cam that engages the shutter speed dial start point.