I am planning to do the headlight wiring upgrade and have a simple question for anyone that has done it.Where is the factory connector from the stock harness that the new custom made harness will plug into it?Is it the old driver side low beam headlight connector?It is circled in blue in the pic?

 

you plug that harness into the connector that used to go to the headlights...

the low beam relay turn on connects to the stock low beam headlight plug

the high beam relay turn on connects to the stock high beam headlight plug

 

As long as your headlights work now, just find the TAN & GREEN wires in the current headlight wiring harness and use these. My headlights were flickering & generally acting stupid because of bad grounds, but since the TAN & GREEN wires were fine, I just tapped into them and never looked back. The headlights are MUCH better than they were even though I'm still running standard incandescent bulbs.

The TAN & GREEN wires can be seen in the schematic below in the bottom-left. I found mine running from the firewall to the front-left headlight somewhere near the steering column, but that's on a '91.

 

not trying to hijack this thread but does anyone know if the high beam lights are the same as the low beam units? the reason I ask is becase I would like to swap the sylvania high beams from my RS and use them for the low beams on my Z28.
thanks

 

They look like they'd mount in the car properly, but when I purchased replacement headlights for my RS, the low & high beams were different part numbers. I think the electrical socket is different, too.