Hoping someone can help me with a couple quick questions. Never done a B swap before and having a few small issues. It is a 1990 Honda CRX HF and an OBD1 B18a1. Firstly, in pic number one what is supposed to connect here? Also in pic #2 I don't think I had anything like that on the harness but I did have #3 which I don't see where it plugs into or what its function is. Thanks

 

#1 is the VSS cable port. This cable plugs directly into your gauge cluster. #2 is the fan control switch, but it is an OBD-1 style plug, whereas, in pic #3 you have the twin post OBD-0 style plug. Simply change the plug style on your old harness (remove the big black rubber cap and the pair of female barrel connectors and splice in a grey round two wire plug that fits the sensor in pic #2) and you are done.