Hi all I have a`83 K5 with diesel. The owner before me did some strange things with it. He took out half the A/C and messed up the eletrics. Couple of weeks ago I found a `89 Sub that was wrecked but the wireharnes was ok so was the heater. But when I take a closer look at the wires its difrent in many ways, the plugs for the doors are not the same. On my `83 K5 i have a red box under the dash, what is that?? The Sub did not have that box so there is no plugg for it. Do I miss some boxes from the Sub maybe?? I just took the harnes with the fusebox. The Sub did not have A/C but it was also a 6.2.