I have an 1989 Honda Civic DX with Dual point fuel Injection. I think that maybe the fuel pump is intermitently not working. I checked the voltage to it on the four wire harness. On the two wires that go to the connector under the rear seat Black/red dot and Yellow/White/red dot when running across them 1.88vdc, same if I measure to ground. On the other two Black/Silver dot and Yellow/Blk/Silver dot I measure 12-13vdc when running. If I disconnect the connector under the cover plate on top of the fuel tank the 1.88vdc reading goes up to 7vdc. So I have two questions. First the connector I just discribed, is that the fuel pump or is that the fuel level sensor? Maybe that would explain the low voltage? Because the car has started working again. But if I disconnect the connector that has the four wires in it that is under the rear seat the car dies very fast, so that means two of them go to the fuel pump.

Also how do you remove the Main Relay? It seems to be mounted under the dash near the left side? I pulled out the tray that covers it, but it still seems very diffcult to get to it?

Thanks

 

I figured out that the connector under the cap under the rear seat is for the fuel gauge. So the 1.88vdc is from the sensor. So at this time the 12-13vdc on the other two wires has to be for the fuel pump. So if it stops again I will check the voltage there first, and the ground.

I can't believe that the Main Relay is put is such a hard place to get at it?

Thanks

 

welcome to the forum. there is a diagram in hondacarforum search for civic main relay.