Which wire for fuel-pump kill switch...?

[snail]

Because I dont know where it is?:eyes:

Same here haha. The 'interrupt in-line' method went over pretty clean for me and took only 15 minutes so I probably just going to do it again.

FYI for anyone: 97+ the wires running to the fuel pump are easy to see right where they go into the pump, so if you have any doubt about what are the correct colors upstream just double check those. cut one then turn the key and listen for the pump priming. no priming = chose the correct wire

oh man i just went to project xj's site to double check what color (green w/ red stripe i think) and the sites dead now?

 

[lazyxj]

Here is a trick that will drive thieves nuts.
Wire a slow-blow fuse across the kill switch terminals.
When the switch is in the anti-theft position (off), the slow-blow fuse will allow the engine to start and run for a few seconds before blowing.
This usually gives the thieves enough time to get the vehicle out in the street before the engine dies. Not a great place to be searching for a kill switch.

I did this to my VW many decades ago. One night I heard the engine fire in the driveway and by the time I got out of bed and to the door, it was sitting in the middle of the street with a guy running away from it.
Turning the hidden switch to the 'run' position allows the engine to run normally.

You need to experiment to find the right fuse value. I start by measuring the amperage draw of the circuit and then buying several different fuse whose sizes are around the average amperage draw. Trying different size fuses allows you adjust the run time.
If you use a DPDT switch, the other set of contacts can be used to power a dash mount flashing LED light that will act as an alarm light and as an indicator so you do not drive off without deactivating the cutout.

 

[Markos]

Here is a trick that will drive thieves nuts.
Wire a slow-blow fuse across the kill switch terminals.
When the switch is in the anti-theft position (off), the slow-blow fuse will allow the engine to start and run for a few seconds before blowing.
This usually gives the thieves enough time to get the vehicle out in the street before the engine dies. Not a great place to be searching for a kill switch.

I did this to my VW many decades ago. One night I heard the engine fire in the driveway and by the time I got out of bed and to the door, it was sitting in the middle of the street with a guy running away from it.
Turning the hidden switch to the 'run' position allows the engine to run normally.

You need to experiment to find the right fuse value. I start by measuring the amperage draw of the circuit and then buying several different fuse whose sizes are around the average amperage draw. Trying different size fuses allows you adjust the run time.
If you use a DPDT switch, the other set of contacts can be used to power a dash mount flashing LED light that will act as an alarm light and as an indicator so you do not drive off without deactivating the cutout.

If you install a fuel pump kill switch and have a good fuel pressure, the Jeep will do this anyway. I don't recommend that you install a fuse. I've had my kill switch for 5 years and can't count the number of times that I've tried to start the Jeep with the kill switch on. I'd hate to start it up thinking that the kill switch is off, only to blow the fuse. The fues will work once and won't have any end effect on the theft of your vehicle.

Regarding the switch. A 20a rocker switch on the fuel pump ground wire works fine. However, I recommend a quality switch. I use the black plastic round 20a radioshack toggle switch. The switch runs hot, and will fail after about a year. I keep a spare in the jeep, along with a jumper wire to bypass the switch altogether. The RS switch works fine, just plan on replacing it every now and then. I've gone through 1 a year for 5 years. They only cost a few bucks.

FYI - No CEL activation on my '99

 

[lazyxj]

If you install a fuel pump kill switch and have a good fuel pressure, the Jeep will do this anyway. I don't recommend that you install a fuse. I've had my kill switch for 5 years and can't count the number of times that I've tried to start the Jeep with the kill switch on. I'd hate to start it up thinking that the kill switch is off, only to blow the fuse. The fues will work once and won't have any end effect on the theft of your vehicle.

Fuses are replaceable if you blow one.
The flashing LED is an indication for YOU to flip the switch to keep from blowing the fuse.
The LED can be wired to flash all the time or only when the ignition is turned on.

This method can be used on all circuits, not just the fuel pump. I have used it for almost 40 years on ignition and injector circuits.

 

[Ivan]

Better than the fuel pump relay, put a switch on your ASD relay. By disabling the ASD relay; that prevents the fuel pump, ignition coil,and injectors from powering up. I sometimes remove ASD relay as a "poor man's anti theft measure. One of these day's I'll just wire a switch to it, and be done with it...

 

[garr]

Better than the fuel pump relay, put a switch on your ASD relay. By disabling the ASD relay; that prevents the fuel pump, ignition coil,and injectors from powering up. I sometimes remove ASD relay as a "poor man's anti theft measure. One of these day's I'll just wire a switch to it, and be done with it...

Good Idea, But will it throw a code on later model Xjs?

 

[lazyxj]

Better than the fuel pump relay, put a switch on your ASD relay. By disabling the ASD relay; that prevents the fuel pump, ignition coil,and injectors from powering up. I sometimes remove ASD relay as a "poor man's anti theft measure. One of these day's I'll just wire a switch to it, and be done with it...

Like I said in the previous message, you can use the slow-blow fuses on almost any circuit; ASD relay, injectors, fuel pump, coil rail or whatever.
Here is the reason why I like using slow-blow fuses. Usually thieves try to control the situation by picking a vehicle that is out of sight so they can work on getting it started without interruption. If it does not start right away, they can continue to work on it.
Letting them get it started and 50-100' down the road before the engine quits changes the whole game. Most thieves are not going to sit there and try to figure out what happened while stalled in the middle of the street.

 

[Ivan]

Like I said in the previous message, you can use the slow-blow fuses on almost any circuit; ASD relay, injectors, fuel pump, coil rail or whatever.
Here is the reason why I like using slow-blow fuses. Usually thieves try to control the situation by picking a vehicle that is out of sight so they can work on getting it started without interruption. If it does not start right away, they can continue to work on it.
Letting them get it started and 50-100' down the road before the engine quits changes the whole game. Most thieves are not going to sit there and try to figure out what happened while stalled in the middle of the street.

Though I understand your logic, that could leave you open to liability. Most auto thefts occur at night, under the cloak of darkness. If a thief were to make off with your rig and leave on the road, someone could run into it and injure themselves. I seem to recall such an incident occuring in the L.A. area where the car owner was held liable for such a situation.

By rendering the vehicle inoperative where it sits, it is not likely to go anywhere. If someone wants my XJ bad enough, they'll simply tow it.

You have to be creative where you hide the kill switch. I have a stock replacement steering wheel I bought on Ebay that came with cruise control buttons, to replace my stock one because the leather is peeling. Yet I have no cruise control feature on my XJ. I thought of using one of those button as my kill switch. I also have WJ seats with several seat adjustment switches that are of no use since I mounted the seats on the stock XJ seat rails. One of those switches now controls my garage door opener. I could also use one of the spare switches as a kill switch. A friend of mine even went as far as to drill another hole in his A-Pillar plastic molding, mount a push button on/off switch, and then camoflage it with another matching plastic plug, that is used to hide the screws that hold the A-Pillar plastic molding in place. You can't even tell it's there, unless you notice there are three plugs on the driver's side A-Pillar molding, and two on the passenger side.

As far as throwing a code, I'm not sure if it will or not. I've never had to test that because for now, I simplyu replace the ASD switch before I turn over the engine. Again, one of these day's I'll permantly wire the kill switch in. I only pull the ASD relay when I feel uneasy where I park my XJ, such as when I'm out of town and such. The rest of the time, it's locked in my garage....

 

[Markos]

Fuses are replaceable if you blow one.
The flashing LED is an indication for YOU to flip the switch to keep from blowing the fuse.
The LED can be wired to flash all the time or only when the ignition is turned on.

This method can be used on all circuits, not just the fuel pump. I have used it for almost 40 years on ignition and injector circuits.

To each there own, but I see this as nothing more than added complexity. Now you need a flashing LED to remind yourself that the kill switch is activated. The LED also clues thieves into some type of security system. This may work great for you, but I know that I'd need to constantly replace the slow blow fuse because I didn't flip the switch. There are so many simple options out there that achieve the same thing. I can also say that my simple kill switch has worked great for x amount of years, but nobody has ever broken into my Jeep.

 

[ColoradoRaptor]

If I were a thief I would look here and see what you yahoooo's have done to try and foil my plans of joyriding your Junk :laugh:

 

[keep0njeepin0n]

I have a stock replacement steering wheel I bought on Ebay that came with cruise control buttons, to replace my stock one because the leather is peeling. Yet I have no cruise control feature on my XJ. I thought of using one of those button as my kill switch.

I did that same sort of thing on my 99...I used the factory fog light switch that I bought off ebay. I had no factory fog lights, but what thief is going to say HEY, this guy doesn't have fog lights, what's this switch doing here?

In fact, as a joke to my buddies, I used to tell them I'd give them $20 if they could start my Jeep....nobody ever collected!

 

[snail]

oh man i just went to project xj's site to double check what color (green w/ red stripe i think) and the sites dead now?

EDIT IMPORTANT: the 1997 fuel wire is GREEN w/ WHITE STRIPE, not green w/ red. there are two of them in the harness, slightly different thicknesses. either take a lucky guess or crawl under where the wires meet the fuel pump and try to judge the thickness and compare.