I have some trucks that we still use of that vintage, but not IH. There are not many wires under the dash of any of them. I also joined this forum because of issues that I was having, but with IH industrial equipment. I received lots of invaluable advice, but there was still a lot to figure out on my own. These big projects are not for the novice. There is a reason you don’t see a lot of IH trucks and equipment anymore that were once very popular. Technical knowledge has been lost to time. Parts are difficult to come by. There just is not a kit or a diagram for everything needed on these relics. There are some on this forum who make these projects look easy, but that is only because of how talented some on this forum are.