fuel shutoff switch

[james750]

Looking at some simple anti theft measures on the MJ. A fuel pump cutoff switch is the most simple and most effective measure I have thought of. I have heard that the wiring for the fuel pump runs along the drivers side under the trim at the bottom of the door. Which wires are for the fuel pump, and is one possibly a ground wire as I'd rather interrupt that than a positive lead?

[jimoshel]

Look under the left kick panel.There is a 10 pin grey plug. Pink with Black tracer is the hot fuel pump wire. The ground is under the bed on the frame.

[the_wizard_of_fire]

you really want a peice of un-grounded electronics in your gastank? :no: switch the hot lead, my friend. its just safer.

[Eagle]

you really want a peice of un-grounded electronics in your gastank? :no: switch the hot lead, my friend. its just safer.

Good point. Electrical current seeks a ground. If you interrupt the ground kindly provided by the factory, it'll seek out a ground path anywhere it can. It's just the nature of the beast.

[64 Cheyenne]

An easy way to do this is to splice a fuse holder into the hot wire, behind the kick panel 1 - hot wire in, 2 wires out, 1 - hot to the fuel pump, 2 - goes to a switch that goes to ground. this way you can put your switch just about anywhere convenient without taking the hot wires to it. when you want to disable your fuel pump, close the switch, if the truck is started the fuse blows, fuel pump shuts down.....no go no mo. :clapping:

To restart, open the switch, replace the fuse.

[jpnjim]

An easy way to do this is to splice a fuse holder into the hot wire, behind the kick panel 1 - hot wire in, 2 wires out, 1 - hot to the fuel pump, 2 - goes to a switch that goes to ground. this way you can put your switch just about anywhere convenient without taking the hot wires to it. when you want to disable your fuel pump, close the switch, if the truck is started the fuse blows, fuel pump shuts down.....no go no mo. :clapping:

To restart, open the switch, replace the fuse.

 

That's hardcore. :yes:

 

Hopefully anyone doing this has:

1) a very good memory (= never leave the switch on accidentally)

2) a spare fuse with them where ever they go (incase #1 fails, or someone does try to steal it)

3) Friends, family members, and significant others who might end up driving it who also have #1 & #2 above.

 

 

 

It's good because you don't have to worry about a remote mounted kill switch carrying current to the fuel pump (as in a typical kill switch setup) failing over time,

 

The 'dead short' switch is electrically irrelevant, until you close it.

 

 

Just make sure no one hits the "conveniently mounted switch" while you're cruising down the road,

or you'll be to coasting over to a stop

popping the kick panel to dig out the hidden fuseholder

locating your spare fuse

and changing it right there

(hopefully not while other cars are wizzing by, inches away @ 80mph :eek: ).

[jimoshel]

Frankly I really don't like the idea of tapping into the wiring. Prefer to go to a junction where I can add what ever I have in mind. What I do is remove a fuse to the circuit I want controlled. Two spade terminals, one in each side of the removed fuse socket. Two wires going from spade terminals to switch, inline fuseholder in one of the wires.Switch behind ashtray or cigar lighter. Ashtray in, circuit closed. Ashtray out, circuit open. Want to remove it, pull the wires, reinsert the fuse. No mods or damage to wiring.

[Geonovast]

you really want a peice of un-grounded electronics in your gastank? :no: switch the hot lead, my friend. its just safer.

Good point. Electrical current seeks a ground. If you interrupt the ground kindly provided by the factory, it'll seek out a ground path anywhere it can. It's just the nature of the beast.

 

:agree: :agree:

 

You may notice that no fuse is on a ground. It's always on the positive side.