electrical ghost issue

[cob427sc]

I've built a lot of cars over the years and I will be the first to admit that electric areas are not my strong point. My 33 is getting close to completion and as I complete the installation of the headlights I have an issue that boggles my mind. I am running the daytime driving lights and ran the extra wires as instructed in the manual. The lights all work - hi/low beam, daytime. directional and hazards. The problem is that the electric fuel pump runs all the time! The only way to shut off the fuel pump is to disconnect the parking light feed wire. Somehow power is feeding back through the harness/fuse panel. Anyone have suggestions?

[JimLev]

What engine/ECU are you using?
The fuel pump should either be powered from a 12 volt source (relay) when the ignition is on, or from the ECU, usually a relay too.

[cob427sc]

No ECU. Engine is 1958 Buick Nailhead. Electric pump comes on even with ignition key in the off position, that's the quandry. How is power back feeding through the system to turn on the fuel pump (and what else?). I have disconnected the feed wire for the parking lights and this shuts off the fuel pump but doesn't allow the parking lights to work off the light switch for the front lights. Otherwise all the lights work properly. I used the power source to the headlights to be fed off the electric choke wire (as suggested in the manual) to power the lights. Fuel pump lead is the wire included in the regular harness.

[Robodent]

I had a couple wires in my Ron Francis harness that were flipped in the rear harness. Where the rear harness plugs into the main harness. Sounds exactly what I went thru. I had a friend that had the pin tool kit to remove the pins in the plug to line everything up. Hope this helps . I’m not a wire genius either. Rob

[Just puttering]

Disconect the wire at the fuel pump attch a wire to its wire and run it up to the fuse panel area, attach it to one side of your multimeter (if you need one, I picked up a decent one at home depot for $20), use the other probe of the multimeter to check what the fuel pump wire is attached to! Set the multimeter to OHMs, With the power OFF check your wiring. Also check with the fuse in and pulled to narrow down your findings. Most digital multimeters have a diode setting close to the OHMs stting that will make it buzz when the leads are touched together, using this, you dont need to look at the meter, just listen for the buzz.

[GBPCAZ]

You probably figured this out by now but maybe I can help the next guy or gal.... The relay is wired wrong. The signal is "hot" all of the time. You need to eliminate that and find a "switched" source and that will solve the problem.