Starter Relay Wiring
You need to get yourself some documentation. These aftermarket diagrams are ----ok---- under some conditions, and somewhat easy to follow compared to the factory diagrams, but when you are trying to figure out connectors, there is no substitute for the orginal diagrams. You can download quite a few years of these free at MyMopar. Some of those came from the guys here on FABO
There is one caution.......there was a few years where the bulkhead connector is wrong..........the yellow start wire and the green/ red horn wire is reversed at the bulkhead connector
http://www.mymopar.com/index.php?pid=31
One really great thing now, at that site, is they have posted ONLY the factory wiring section out of the shop manual, making it a much smaller file:
mymopar.com/downloads/1970/70_Dart_Challenger_Wiring_Full.pdf