Adding auxillary input to original Delco radios

[TaylorL]

My dad bought my 85 K10 shortbed brand new. He put 400,000 miles on that old 6.2 diesel and 4 speed before parking it in 2007. I got it back on the road in 2016, since then the diesel cane out in favor of an ls swap and an nv4500. It's been a ton of fun restoring and modernizing my dad's old k10. One of the things that I've really wanted back was the original radio. I still have the original but it had some issues so I swapped it out for a cheap single din radio to get me by. Though nothing beats the looks of an original Delco radio in the dash of our trucks, not even a retro sound. The trouble is for the most part a modern radio is our only option for any kind of auxillary input to play music off our phones. With some determination though I found a way to add an auxillary input to our original Delco radios. Particularly the gm2700 series. Basically there are two wires that come out of the tuner heading for the volume pot. You must cut these wires in the middle, splice the tuner leads into the input of a switched auxillary jack from radio shack and the two wires going to the volume pot solder into the outputs of the jack. Ground it and your done. This way under normal conditions your radio works like original with am/fm functions. But when an auxillary cord is plugged into the jack the am/fm tuner is disconnected and the auxillary cord becomes the input. The auxillary jack can be remote mounted under the dash discretely. Everything will look and function as original until you plug into the hidden auxillary input.