xyoung347x

at the moment I have Aftermarket sub and amp using the add-gm24. I want to update the HU from stock and keep my aftermarket sub and amp. What harness is needed? Can I use the ADD-GM24 or requires a different harness? I've been searching for hours but my internet is CRAWLING!

markcz

Do you have OnStar, and do you want to keep it functional?

Are you going to add aftermarket speakers and a new amp, or just keep current speakers/sub as-is with the new radio?

xyoung347x

Don't need onstar. Keeping my aftermarket subwoofer and aftermarket amp.

xyoung347x

lunch time bump.

markcz

You can leave the Add-GM24 in place and just add a C2R-GM24 or RP3-GM11 in front of it for the new radio, or either of those two adapters on their own. Neither will retain onstar or steering wheel controls. If you have SWC you can add the HU specific interface or just get an RP5-GM11 on its own.

If you call Dennis at DoubleDmods.com he can set you up with the best one for your situation.

xyoung347x

Thank u sir. One last question. Can I use the aftermarket hu for the amp and ditch the ADD-GM24 or do I still have to use the ADD-GM24 for my amp/sub setup?

markcz

If your new HU has a separate RCA sub output, use it and ditch the Add-GM24. If not, leave the speaker outputs on full-pass (HPF and LPF off), connect the four RCA outputs to the new interface adapter, and leave the Add-GM24 in place.