Inertia fuel pump and battery kill switches

[Dave]

I just finished wiring a electric fuel pump to the stock wiring in my 71Z.

The fuel pump wiring is already in the car from the factory. There are

2 wires taped with blue tape at the fuel level sender at the tank The

black wire at the fuel pump is grounded to the chassis at some point

between the pump and the dash. The green wire is + The other end

is behind the radio taped to the harness with blue tape. To run the

pump you simply need to supply 12+ to the green wire in the harness

behind the radio. Its a mystery to me where the black wire in the

harness behind the radio goes.

 

There were already holes in the 71Z on the right side just in front of

the tank that matched the 280Z pump bracket that I used. I used a

Fram FRAM G-3 clear fuel filter between the pump and tank. Its $4

at the local Wall Mart store

 

What I did on the rest of the wiring was to use the oil pressure switch

to control the pump with the 3rd connection going to the starter

solenoid to run the pump when its cranking since using the oil pressure

only will prevent the pump from running until the car starts.

 

Last but I felt most important I put a fuel pump inertia shut off switch

in the car on the drivers kick panel and wired it between the fuel pump

side of the relay and the green wire in the harness behind the radio. I

did not cut up the harness I simply used a male spade connector and

shoved it into the green side of the plug to make the connection.

 

The inertia fuel pump shut off switch will shut off the power to the

pump in the event you have a accident. It also will shut it off if you

hit a speed bump going too fast. It happened to me once when I had

the intertia switch under the hood. That is the reason I moved it in

to the car where I can reach it. That one time is the only time it has

shut off. The inertia switch has a reset button that you simply push

to reset it.

 

The inertia switch is from any fuel injected Ford from 1980-2000. its

in the trunk on the left side behind a panel that is almost always

marked that the emergency fuel cut off is behind it. Be shure to cut

the harness as far back as you can when removing the switch. With

out the 2 wire harness its going to be hard to connect

 

A anti theft fuel pump switch can be placed before or after the inertia

switch to cut power to the fuel pump if you want.

 

Now I went 1 step further and used a second inertia fuel pump shut

off switch to control a main battery solenoid shutoff. Instead of using

a manual battery disconect like every one else uses I have a solenoid

designed to disconnect the battery. The solenoid is the same one used

on Piper, Cessna and Beechcraft to disconnect the battery when the

aircraft are parked. The solenoid is 6 inches from the battery and I

chose to disconnect the Positive cable. I was going to use it on the

negative cable but I have the alternator output connected to the

positive cable at the battery and the engine would still want to run

in a accident for a short period of time if the negative was disconnected.

This inertia switch is also on the drivers kick panel next to the one for

the fuel system. In the event of a accident the battery will disconnect

as will the fuel pump power. A simple double pole single throw toggle

switch can be used as a emergency or antitheft switch. that will kill

both battery and fuel. Or you can use a switch or each and hide it

where ever you want. This is as fail safe as it gets with inertia switches

and the battery positive being disconnected with in 6 inches of the

battery.

 

I have a picture of the aluminum plate (Soon to be painted black)

that has both inertia switches and a double pole single throw disconnect

switch between the inertia switches. The disconnect kills both the

fuel pump and battery

 

http://63.229.133.5:8884/Files/Datsun/Inertia-Switch/Switch-Med.jpg

 

I used this aluminum plate so I could easly remove the complete assembly.

Once painted its hard to see and the kill switch is hidded between the

inertia switches. At this point its easy to put in a second set of switches

if needed.

 

I have a couple extra inertia fuel pump shut off switches if any one

is looking to do this modification and does not want to go to a wrecking

yard to get one. I may even be able to get some more of the battery

disconnect relays. But at $40 each they are expensive!!!!

[cygnusx1]

Yes, I use the search engine!

 

I just ordered two FoMoCo inertia switches from Amazon.com. Got them for $20 each. If you have a direct wired fuel pump, go order one of these bad boys and wire it into one of the fuel pump wires ASAP.

 

http://www.amazon.co...duct/B0044A7U9G

 

 

 

 

 

 

 

Edited February 22, 2011 by cygnusx1