Tony: I have late '71 S2 OTS w/ A/C, but unfortunately mine's still in winter storage 45 mi. away, and have only one lousy pic of this area. Per JCNA judge guide, the horn relay would be one top, alt fan relay in middle and A/C fan relay on bottom. If you have any carb cleaner you may be able to clean to see colors. Here's a wiring diagram showing the relay contacts and what goes to them. If you are still having problems, you should be able to use a circuit tester to
1. continuity unknown wire to end fuse #6: this will be for the contact C2, alt relay.(green)
2. continuity from unknown wire end to fan motor. This would be attached to alt relay contact C1 (it may be the double wire). (black/green)
3. continuity from unknown wire end to otter switch. This would be attached to alt relay contact W1.
(black/red)
4. continuity from unknown wire to A/C switch (dash). This would be attached to A/C relay contact W2. (blue wire)
5. Beyond these, you should have a jumper wire from both C2 contacts and also between both C1 contacts.
