I drive a 78 Buick Regal it has a factory original delco radio in it... I have purchased a new double din pioneer headunit and purchased a gbody wiring harness to hook up to the factory unit... I had trouble getting the wood face off the center console so I got on the ground and unplugged the 3 main wiring leads from the backside thru the gaps but I can not find the 4th battery constant wires. I’m beginning to think they don’t exist on this old model since it probably ne’er stored the time before but I don’t know what to hook my new unit up too now cuz when I turn the car on the new headunit isnt starting when all wires are plugged in except the constant yellow connection... I read online that some people wire the yellow to the 12v battery ignition wire but idk if that’s such a good idea or if I’m suppose run a new wire to the battery for a constant