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

[ctilsie242]

A friend of mine has an E-450 based class "C", which nearly was stolen, but the thieves couldn't get away with the vehicle due to a dead engine battery.

To prevent this again, I was proposing something I did on my first car back in the 1980s -- a kill switch. This would go on the engine fuel pump wire, and be placed in an out of the way location in the motorhome.

Of course, it goes without saying that the splices will be done "right" with solder, heat shrink tubing, and a Western Union style of wire wrapping.

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

[ctilsie242]

The main reason for this theft deterrent is that the vehicle doesn't have a PATS system. So, it is pretty easy for a thief to break out the ignition lock. Anything is better than nothing in this case.

Here is what I'd use for a key switch:



I am going to look at something for the starter. That way, if I totally hose up the splice, the vehicle doesn't start, as opposed to the risk of it shutting down on the road.

[GordonThree]

wa8yxm wrote:
The answer is YES it is safe to splice the wires provided it is done properly.
It is ALWAYS safe to splice wires provided they are not "hot" (that is energized) when you splice them and do it properly.

Use a linesman type splice, not a rat tail and if the splice is exposed to weather use marine grade heat shrink (Get it at a marina) to seal the splice.

note many eo this some put it in the fuel pump lead, some in the starter lead.

If the wires being spliced are power wires I agree.

If they're network wires, CANBUS for example, splicing one of them might cause big problems, regardless of the quality of the splice work.

[wa8yxm]

The answer is YES it is safe to splice the wires provided it is done properly.
It is ALWAYS safe to splice wires provided they are not "hot" (that is energized) when you splice them and do it properly.

Use a linesman type splice, not a rat tail and if the splice is exposed to weather use marine grade heat shrink (Get it at a marina) to seal the splice.

note many eo this some put it in the fuel pump lead, some in the starter lead.

[MEXICOWANDERER]

https://www.allelectronics.com/item/ksw-33/on-off-keyswitch-remove-key-in-off-position/1.html

[MEXICOWANDERER]

If someone

really really

wants your car

they'll knock on your door, and you will be glad to wash the windshield so they and their cannon size bore magnum pistol will get out of your face.

Down here they'll come at night with a tow truck. Then drag the car up onto a Jerr Dan tilting flatbed tow truck. Quick action with a double pump aluminum jack and trolley wheels makes it all relatively quiet.

But there is a work around. I know the secret. Pfffftttt!

My car is so ugly they'd rather eat their gun than be caught stealing it. My dog poop and a rock wrapped birthday present box on the back seat is entertainment. I have to clutch the door handle when I return from shopping and find somehow they had managed to unlock the door when the window was rolled down a mere two inches for ventilation.

[John_Joey]

If he's afraid it's going to be stolen while in the driveway not being used 95% of the time, then just pull a tire off and then lower the axle onto a jack stand where a tire can't be slide back on.

Or move to a safer area.

[Chum_lee]

Look in the fuse box and find the fuel pump relay. Remove it and you're not going anywhere soon. There will be an additional empty relay socket in the fuse box. To get sneaky, pry the cap off the relay and force it to fail then put the cap back on, or cut the powered signal spade terminal off. (or find an old failed relay) Then replace it in the fuse box. The vehicle won't run. Buy a new relay for use when you want to drive the vehicle and exchange the bad relay for the new one. Most thieves don't want to spend the time to diagnose your bad fuel pump relay issue and will move on when the vehicle wont start. But, . . . . the most determined people will figure this out given enough time, or, if they see you regularly switching relays. Try not to cut factory wires or add non-factory wiring/switches because experienced thieves will spot it right away.

Chum lee

[ctilsie242]

What Mexicowanderer stated is why I don't like Ravelco or other third party ignition disable devices. A kill switch, if spliced in and soldered in right, with head-shrink tubing to ensure oxygen stays out, will add a low failure risk. However, it might be better to just pull the starter relay, so nothing that is running is affected.

I might go down that road. I have seen some modified starter relays that use remote controls like the Cyclops TAM. It won't stop a dedicated thief, but it will stop the tweaker who knows how to use a screwdriver in an ignition switch. Plus, it doesn't require cutting and splicing.

Removing the battery is an answer, but the person I offered to help with has back problems, so it isn't an option.

[GordonThree]

keep it simple, remove battery when not in use?

[fischer]

Battery knife sw

[MEXICOWANDERER]

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 🙂

[GASMAN6674]

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

[GordonThree]

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.

[azrving]

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