If it's not original then likely not added to the harness. Easy to run an extra wire back, even just to test. Common plug if you want that too.
I added a NOS one to mine, came with some parts but no harness. Easy to add. I see a guy on ebay was selling his own harnesses, essentially he was grabbing a roll of wire and adding a plug to each end and calling it done! Not sure if he had any sales.
It's also an option, not sure it was ever part of the harness. I'll add a relay to mine, allow keyless trunk option from key remote to pop. Leave the glove box button and key as a back up.