The closest wiring diagram I have that would be similar to a 1988 Dakota is one for a 1988 Dodge Caravan. Since for engineering design purposes the first generation mini-van was considered a truck, I would expect wiring diagrams to be similar if not the same.
The 1988 Caravan has 2 connectors at the fuel tank. One for the fuel pump which is 2 wire, Dark green / black tracer which is 12 volt power and gray which is ground. There is another 3 wire connector at the fuel sending unit. Gray which is ground, light blue which is signal for low fuel lamp, and dark blue which is signal for the fuel gauge level indicator.
Is the fuel tank metal on your vehicle? In 1988 I believe Chrysler was still using metal fuel tanks on cars and trucks and mini-vans. I believe the switch to plastic tanks occurred around the 1991 model year.
You mention a 5 prong connector at the fuel tank. Through 1990 the fuel tanks were metal and there were 2 openings in the top side of the tank. One was for the electric fuel pump and one was for the fuel sending unit. Since these were separate devices the wiring connectors were separate as mentioned. The electric pump has a 2 wire connector and the fuel sending unit has a 3 wire connector.
I suspect that a previous owner swapped in a later model plastic tank(???) with integrated fuel pump module (pump and sender combined) with the combined 5 prong wiring connector. And somehow that 5 prong connector was spliced (or attempted to spice) into the 1988 wiring. The green wires you mention at the tank do not match the wiring scheme for a 1988 Caravan.
I think you have a real wiring mess on your hands. You will have to find fuel level sensor wire at the sensor and trace it back to instrument panel. You might have to unwrap wiring harnesses along the way to make sure you follow the correct wire. This will be tedious.
The 1988 Caravan has 2 connectors at the fuel tank. One for the fuel pump which is 2 wire, Dark green / black tracer which is 12 volt power and gray which is ground. There is another 3 wire connector at the fuel sending unit. Gray which is ground, light blue which is signal for low fuel lamp, and dark blue which is signal for the fuel gauge level indicator.
Is the fuel tank metal on your vehicle? In 1988 I believe Chrysler was still using metal fuel tanks on cars and trucks and mini-vans. I believe the switch to plastic tanks occurred around the 1991 model year.
You mention a 5 prong connector at the fuel tank. Through 1990 the fuel tanks were metal and there were 2 openings in the top side of the tank. One was for the electric fuel pump and one was for the fuel sending unit. Since these were separate devices the wiring connectors were separate as mentioned. The electric pump has a 2 wire connector and the fuel sending unit has a 3 wire connector.
I suspect that a previous owner swapped in a later model plastic tank(???) with integrated fuel pump module (pump and sender combined) with the combined 5 prong wiring connector. And somehow that 5 prong connector was spliced (or attempted to spice) into the 1988 wiring. The green wires you mention at the tank do not match the wiring scheme for a 1988 Caravan.
I think you have a real wiring mess on your hands. You will have to find fuel level sensor wire at the sensor and trace it back to instrument panel. You might have to unwrap wiring harnesses along the way to make sure you follow the correct wire. This will be tedious.