mSo the interesting part... running the fuel pump off the original harness.
The diesel tank has an in tank fuel sender which uses 3 wires. 2 sender wires (Purple/BlkWht) and a ground. The diesel lift pump underneath the drivers door uses two wires (tan/black) to run the lift pump, which is ran off the OPS circuit. (Tan=Power, Black=Ground)
The gas in tank fuel pump uses 4 wires, (purple/blkwht/grey) and a ground. Purple/BlkWht run the fuel sender, and the grey powers the lift pump.
I was able to find the female end of the fuel pump harness off of a junked 88 GMT400 truck.
I made an extension cable that plugs into the lift pump socket, and extends two wires (power/ground) to the rear of the truck where the new in tank fuel pump will go. The lift pump will be replaced with a factory replacement fuel filter for a 94 gas truck.
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Below is the socket for the fuel pump. which I combined with the original diesel sender harness and my custom harness. (which plugs into the lift pump circuit which runs off the OPS) The wiring at the tank will now plug directly into the fuel pump without any wiring modifications making it significantly easier to replace down the road.
Also the fuel pump runs off the OPS as the original trucks did, for safety reasons.
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I'm currently working on making a parts guide/owners manual for this truck, so anyone will be able to work on it/service it down the road. That way should the fuel pump need replaced, you'll just give the parts store representative the year make and model for a gas truck and the pump will be a direct replacement without any modification. The fuel system has essentially been converted to a gas truck, so really the only difference is you use a gas fuel pump/filter. everything else (except maybe the radiator) stays true to the diesel truck. The carb is a very simple set up with hardly any unique parts.
I really want to make sure I'm not the only one who will know how to work on it. That's my biggest beef with conversions sometimes. People build something that only they know how to work on.. This truck will use all the same replacement parts as a typical gas truck and won't require special work. The carb will sacrifice a little MPG and reliability but is fairly self explanatory and won't require any hacks of the original harness.
I doubt anyone would ever want to buy this truck, (I myself would never buy a conversion off someone else) but it really keeps it simple. I also have the flexibility to Cummins/454 or do another swap on the truck down the road with very little modification should I ever want to do so. I'm keeping the dual batteries and would just need to unplug the lift pump extension, and put the factory 6.5 fuel sender/lift pump back in.