So I have a 2015 Suburban, got it salvaged, I rebuilt it and every thing works as it should. With one exception - steering wheel control backlighting. Steering wheel airbag was deployed so I did replace the clock spring. GM part not after market. So what I’m looking for exactly is, what wire in the clock spring wiring supplies the power for the backlighting?. I’ve tried online sources but no luck. So before inquiring with a dealer I thought this community might be able to lend some support. I have an aftermarket radio. Not sure that matters but one of the AI answers on Google gave me some scenarios where the radio is part of the controls for the steering wheel controls backlighting?

Thanks in advance for any helpful resources and or info.