Fuel Pump Wiring

As you might have noticed in images from some of my previous posts the only plug visible was the two prong plug for the fuel pump, and this was worrisome for me. I was not sure that the plug from the front wiring harness for the fuel tank sending unit was still there, or if Short-cut Joe had simply cut it off because it seemed un-necessary. Fortunately I did find it after a bit of digging; it had fallen fairly far back under the lip under the spare tire area.

What I realized while digging for the plug is that there is a ton of leaves in this area as well. How the leaves got in there, I can only guess. Unfortunately they are going to be impossible to remove with out dropping the fuel tank. Having them there could be a problem in the future when the car starts getting driven in normal conditions; the leaves could retain moisture and cause the frame to rust. Frame rust = bad, and I do not want any frame rust to develop, so this is going to need to be addressed; something else to add to my list of things to do.

Neither of the plugs from the front harness for the fuel pump or the fuel sending unit were in use, and the yellow and red wires you see in the image in the center bottom were what was actually being used to power the pump. The real question is why? I have to wonder if there is a problem with the front wiring harness, otherwise why bypass a perfectly good plug? On possibility is that the connections on the fuel pump in the car were different from the standard ones. The connections on the wires that were powering the pump were the type that slide over a tab, rather than a ring that gets attached via a screw. Is it possible the mecahnic did something noble and saved the plug in case the fuel pump needed to be replaced again in the future, and just added the new wires to bypass the front harness and hook up this fuel pump with out mangling the front harness? That would be the best case scenerio. However I think this is unlikely, because why go through all the effort to run new wires undeneath the car when you could hook up right here?

The worst case scenerio is that there is something wrong with the front harness and it isn't getting power, so rather than trying to find the problem with the harness the mechanic just bypassed the harness and jerry-rigged this setup. It seems quite feasible that the rodents that made this car home for many years could have chewed up the front harness. This image is taken from the passengers side wheel well and shows a shot of the wires the mechanic ran to power the fuel pump. You can see the red wire is bolted underneath one of bolts for the fuel tank closing plate - presumably this is the ground. The other wire (now black) can barely be seen here, it is routed back under the frame. Where the black wire ends, I have no idea, perhaps I will find out when I drop the fuel tank.

Another possibility is that there is nothing wrong with the front wiring harness at all, and some how the intertia switch got bumped. Is it possible the mechanic simply did not know anything about inertia switches, and could not figure out why the fuel pump was not getting power, so he added these wires and bypassed the whole setup?

Does anyone want to start a betting pool on which of these options it ends up being?

I hooked the battery back up today so I could do some testing to detemine if I was getting power on the hacked wires, as well as the wires coming off the front harness for the fuel pump. Unfortunately the charge on the battery was really low. I had the battery disconnected over the winter, but it must not have been enough. I now have it hooked up to a trickle charger, hopefully that will do the trick, if not I'll be returning it tomorrow for a new one. If all goes well I should be able to test where I am getting power tomorrow.

Either way, I want to do away with these additional lines for the fuel pump and return the wiring to normal.