1990 and on fuel pump cutoff switch wiring??

[tekctrl]

Trying to find the wiring diagram for the fuel cutoff sensor/impact sensor used in 1990 and later Fords of multiple models. P/n is "5L2T-9341-AA" and wiring connector "5756PT" has 3 leads. Does this sensor use 5VDC or 12VDC? What lead is ground/B+/? I'm wiring this into a new fuel system going into a '57 Chevrolet to cut off the in-tank fuel pump in the event of a collision. Don't want to fry the unit, but don't want to find out the hard way that I wired it incorrectly and it doesn't work.

 

[Pete Deering]

Trying to find the wiring diagram for the fuel cutoff sensor/impact sensor used in 1990 and later Fords of multiple models. P/n is "5L2T-9341-AA" and wiring connector "5756PT" has 3 leads. Does this sensor use 5VDC or 12VDC? What lead is ground/B+/? I'm wiring this into a new fuel system going into a '57 Chevrolet to cut off the in-tank fuel pump in the event of a collision. Don't want to fry the unit, but don't want to find out the hard way that I wired it incorrectly and it doesn't work.

The ford inertia switch has 12 v supply from the fuse block when the ignition switch is turn on. The inertia switch has two wires off of it, both power feed wires go to the pump. Also the inertia switch has a wire off of it, that goes to the dash cluster for a indicator light.

 

[Pete Deering]

The ford inertia switch has 12 v supply from the fuse block when the ignition switch is turn on. The inertia switch has two wires off of it, both power feed wires go to the pump. Also the inertia switch has a wire off of it, that goes to the dash cluster for a indicator light.

I found a general wiring diagram. Its not the same as I described but it for a ford you should get a wiring diagram with the switch.

 

[tekctrl]

No wiring diagram with the switch and no idea which of the 3 wires is Battery, ground, or indicator light.

 

[Pete Deering]

No wiring diagram with the switch and no idea which of the 3 wires is Battery, ground, or indicator light.

Use a ohm meter and ring out the wires or connection. ? What year, makes and model, the switch is for?

 

[Pete Deering]

No wiring diagram with the switch and no idea which of the 3 wires is Battery, ground, or indicator light.

Response to question
1. Uses 12v
2. See attached screenshot
It uses two large conductors in and out ( look like #12) and one small conductor ( look like #18).
3. There is no ground; just a power in and out that gets disconnected by the switch ( on and off). The ground is at the fuel pump. Same for the indicator light; ground is at the cluster.
4. The indicator light, turns on, when the switch is in the off position ( disconnect).

This should be pretty easy to ring out the switch.
What you know is when the button is push in, red button head is below the top of the housing, its in the on position. Use a small screwdriver too lift the button head up too the off position. The small screwdriver goes into the black rectangle opening to ply the button up. Now off or open. Look for the two large terminals
The indicator light terminal is the small one, it will ring out between the power in wire connection ( large) and the small wire connection in the off position( button up).
I don't know how the wires terminate too the switch. Is it a screw terminals or barrel connection.

 

[tekctrl]

Response to question
1. Uses 12v
2. See attached screenshot
It uses two large conductors in and out ( look like #12) and one small conductor ( look like #18).
3. There is no ground; just a power in and out that gets disconnected by the switch ( on and off). The ground is at the fuel pump. Same for the indicator light; ground is at the cluster.
4. The indicator light, turns on, when the switch is in the off position ( disconnect).

This should be pretty easy to ring out the switch.
What you know is when the button is push in, red button head is below the top of the housing, its in the on position. Use a small screwdriver too lift the button head up too the off position. The small screwdriver goes into the black rectangle opening to ply the button up. Now off or open. Look for the two large terminals
The indicator light terminal is the small one, it will ring out between the power in wire connection ( large) and the small wire connection in the off position( button up).
I don't know how the wires terminate too the switch. Is it a screw terminals or barrel connection.

View attachment 437243

All 3 leads are 'bare' or barrel connections. Tested the switch with a battery and a continuity tester yesterday evening. The blue lead and the yellow/white lead had continuity but the red/white was open. I'll see what has continuity with the trigger tripped. Will probably get started on building a wiring harness tomorrow or Saturday if the mercury cooperates. (Unheated garage)

 

[1sicbronconut]

The switches from the 80's only have two wires, I usually use those for my EFI projects.

 

[Pete Deering]

All 3 leads are 'bare' or barrel connections. Tested the switch with a battery and a continuity tester yesterday evening. The blue lead and the yellow/white lead had continuity but the red/white was open. I'll see what has continuity with the trigger tripped. Will probably get started on building a wiring harness tomorrow or Saturday if the mercury cooperates. (Unheated garage)

The blue lead and the yellow/white leads are 12v power circuit. I am guessing the blue and white/ red have continuity when trip. Good luck. I don't like the cold weather either.

 

[tekctrl]

Got it! The middle lead (Blue) is always hot. One of the remaining two is hit until it's triggered, then that lead goes cold and the other lead goes hot. Probably for an indicator light, though why you'd need an indicator light to tell you that you've been hit is a subject for another post. When the sensor is reset, the first lead returns to hot and the second goes cold. Thanks everyone!

 

[Pete Deering]

Got it! The middle lead (Blue) is always hot. One of the remaining two is hit until it's triggered, then that lead goes cold and the other lead goes hot. Probably for an indicator light, though why you'd need an indicator light to tell you that you've been hit is a subject for another post. When the sensor is reset, the first lead returns to hot and the second goes cold. Thanks everyone!

When parked, bumped, or if your car gets towed