Engine Transplant Problems

[HuckMiniCruiser]

I have a 81' Mini Cruiser that was born with a diesel and at some point in its life grew a 20r. When the transplant took place it was in a rather "creative" fashion. My ignition switch, or so I believe it is, is running my carb, fuel pump, distributor cap, and alternator. All of them are wired into this one little wire. There are plenty of other wires here in this harness but I have no idea what they are or where to get a new harness. Any advise is welcome.

[zero]

There isn't any wire-harness that fits what you have. Just wire it on an ad hoc basis. A 1981 diesel had an alternator with a built-in regulator. A 1981 gas engine (22R) had an alternator with an external regulator. Your 20R engine also used an alternator with an external regulator. Fuel pump wiring in a 1981? No. Diesel had no fuel pump at all as I recall, and the gas engine used a mechanical fuel pump. Your 20R has an electric pump. I assume no longer in the right place since I assume you have a 1981 fuel tank? Also - most if not all 1981 trucks with gas engines had emissions-computers. 20R engines did not. So - I cannot imagine of any wire-harness that fits the mix of components you have. If it charges and it runs - seems not much concern other then a safe way to wire the fuel pump. Since you don't have the OEM fuel pump timer and relay for a 20R - seems you need to add something. Installing an engine oil-pressure switch to run your fuel pump with a start-circuit over-ride is one easy way to do it. If the engine stalls - the fuel pump quits. Same way Chevy factory wired the Chevy Vegas in the 70s. Toyota did the same for the trucks with 20R engines but in a more sophisticated way.