Safe to splice the power wires going to a E-450 fuel pump?

IMHO Any time something is employed to disable the vehicle, it has a parts per million chance to malfunction and leave you in a dangerous position. So I treat an auxiliary modification with the care and respect it deserves.

Whatever circuit you choose I would check to ensure that by breaking the circuit it could not cause a fault code to be thrown by the ECU.

A talented thief is all-too-aware of the ten top hiding spots for a kill switch. He can run through all 10 in less time than it takes to read this.

A keyed switch with terminals encapsulated in a nightmare grade compound like Liquid Nails can be hard wired in an inaccessible place like under the front seat. Use huge battery cable heat-shrink tubing over the terminals and then for an additional inch or so onto the wires.

Under vehicle wiring is vulnerable. I would use cross-link polyethylene insulated wire, sheathed in fuel line hose.

When this all seems excessive, imagine looking for a long-gone vehicle then out the side window at a triangle of lights approaching on a railroad crossing...it'll keep you honest :)

Interrupt the power after the inertia switch in the passenger kick panel. Break one wire and route to a hidden switch.

azrving wrote:
There is probably a relay for the fuel pump in the engine bay or in the power center. I suppose he could remove it or wire in a switch as you said. I've done it on a modified Jeep that was insured but sure didn't want to lose it.

Sounds like a good idea. Intentionally blow the fuse for the fuel pump and leave it in there. This way it's not obvious anything is missing.

Starter side of things is the easiest to jump. He needs something not easily bypassed or found.

It would be better to put a switch on the starter relay circuit.

ctilsie242 wrote:
Has anyone done this? My biggest worry is that the connection is a full CAN, not just power leads.

I would not touch this connection.

Since the battery is dead anyway just leave it out. Replace battery when next use is near. Then remove the battery during storage and keep it charged with a Battery Minder or Battery Tender brand maintainer. Solves both issues.

delete double post

There is probably a relay for the fuel pump in the engine bay or in the power center. I suppose he could remove it or wire in a switch as you said. I've done it on a modified Jeep that was insured but sure didn't want to lose it.

Can you just unplug the fuel sending unit from the ECM?