You won't mess it up. With the engine running, pulling the fuel pump relay is how you change the fuel filter. It stops pumping fuel, and it burns off what it can in the line.
People knew 5 minutes after those things were invented how to defeat them. The outside hand grip of your steering wheel is nothing but foam and rubber. You can cut through it in about 3 seconds with a hacksaw blade, and about 5-10 seconds with a swiss army knife. It takes you longer to install it, and lock it, then it does to defeat it.
Along the same idea, I've seen something similar, made out of metal for the gas pedal. Those seem like a better idea. More or less locks it in place.
OP, honestly the best way to defeat it is to add a hidden kill switch.
* Disconnect batt neg.
* 05+ has the fuse cover with the efan relay pack cover attached, so pull the 4 bolts for the corner brace.
* Pull the tabs out of for the fuse panel cover, and tilt the panel in.
* Pull the terminal off the pin for the 30 amp Fuel pump relay.
(#30 is 30 amps power, as in from battery, as in 12v main power feed)
(across (diagonally) is the main switched power, so 87 is to the fuel pump).
(85 is ground, & 86 is trigger wire)
* Now you have the pin off of 87. You can splice into it, you can create a wire with a male spade, but then you run that new wire into the cab, and wire it to, and mount where ever you want to hide your new hidden kill switch. You can put it under the dash, up into the side of the seat under the cover, under the center, under the dash, under the carpet to where it's foot activated.
You have just quickly added a kill switch that can even be hidden from passengers if you wanted to. The other benefit to this is, when you go and park, nobody is going to see you stop and go under the hood, and into your fuse box if someone might be watching.
Honestly just pulling the fuse is kind of silly. You have plenty of other fuses that someone could look at the panel, and swap out, (if someone saw you do it).
Of course someone would still have to break into your vehicle, would still have to beat the key/passcode, and would have to bother with it not starting.
When you say vehicle theft is a problem, you might want to look into what kind of vehicles. Near the Mexico border, they want 3/4 and 1 ton trucks. Every scumbag knows how easy kias are to snag. There's nothing special about a 20 year old tahoe. A 5.3 is a few hundred bucks, and you can get em anywhere. If you don't have big flashy wheels or a stereo that sticks out, you're not setting yourself up as a target. Unless you've added a lot of money in visible parts, there's no money in an NBS 1500.
Nothings a guarantee, but IMO the best thing you can do is, to not make YOUR tahoe a target. Keep the stock wheels on there, Keep the interior empty so people can see there is nothing to take, and don't keep a big subwoofer enclosure in the back. I just don't think people want to steal a tahoe, they would just want your wheels or your stereo, and your tahoe helps them get away with it.
