[L8rhosen]

Hi,

'94 YJ with 4.0L and 5sp manual.
I have been thinking about adding a kill switch. Initially I was thinking about add in a relay and switch to the fuel pump circuit. But.. I am going to be replacing the fuel filter soon (precautionary as I don't know when it was last done).. and I was thinking maybe just adding a simple ball valve cutoff to the fuel line right at the filter. It's already has a plate under it for protection. I was just wondering if it could cause any un-expected issues with fuel system, since it is under pressure. I like the idea of a solely mechanical solution to avoid any electrical gremlins.

Thoughts?

 

[Sgt_USMC]

If you are going to add some sort of kill/immobilizer switch I would do it on the electrical side. Messing with fuel lines isn’t the greatest idea. If something comes loose it’s a fire waiting to happen. You could always add a switch to cut power to the pump or the starter. There are even purpose built switches to disconnect the battery. I’m sure there is some sort of switch and relay setup that would serve you better and safer. That would be a safer way to go about it. Just my opinion though.

 

[L8rhosen]

If you are going to add some sort of kill/immobilizer switch I would do it on the electrical side. Messing with fuel lines isn’t the greatest idea. If something comes loose it’s a fire waiting to happen. You could always add a switch to cut power to the pump or the starter. There are even purpose built switches to disconnect the battery. I’m sure there is some sort of switch and relay setup that would serve you better and safer. That would be a safer way to go about it. Just my opinion though.

Good point on the fuel/fire risk. I'm just talking through ideas. I'll just probably add a switch to the fuel pump or something similar. Just want to get something in before I go completely topless for the summer.

 

[Sgt_USMC]

I completely understand the reasoning for it. I have played with the idea myself a few times. I have heard of reed switches, relays, massive battery switches used for the starter, and tons of other ideas.

Something like they had on mad max fury road in the semi would be pretty cool. Just a nightmare to wire in and hope it doesn’t cause problems! 🤣

 

[StevieTex]

I'd check with a local car alarm installer to see if they offer anything and if so what do they offer. If they do these installs as a routine it might be advisable to let them do the install for you. Not saying you are incapable of it, but someone who does it regularly is usually a better choice in the long run.

 

[Got it at last]

Easiest way is to tap into the wire as it comes up the drivers side. You can hide a switch somewhere convenient from the drivers seat for easy access.

 

[cobra30689]

If I'm really that worried, I just pop out the fuel pump relay and take it with me.

 

[L8rhosen]

Easiest way is to tap into the wire as it comes up the drivers side. You can hide a switch somewhere convenient from the drivers seat for easy access.

I was wondering if that wire loom had what I needed in it.

 

[L8rhosen]

If I'm really that worried, I just pop out the fuel pump relay and take it with me.

That is a brute force way for sure, and I've done just that too!

 

[Got it at last]

I was wondering if that wire loom had what I needed in it.

When I added an electric fuel pump for TBI to my '88 4.2 I tapped into it at the sport bar riser. Had I thought about it I would have put a switch in right there so it couldn't accidently get toggled, yet keep it out of view from would-be thieves.
IIRC Orange wire from the sending unit mixed in with the brake light wiring