It is my recollection that the only electrical reason the relay needs to be on the 70 harness is to operate the headlamp delay circuit should your car have it. I believe the 70 roadlamps will work fine without the relay plugged in unless you have the delay circuit.

71 has the relay to toggle the roadlmaps off when high beams are turned on.

Mike Afflerbach

Cudaize@comcast.net