I'm curious if there are any wires in either the L67 engine's harness, or the harness for the 4t65e-hd tranny, that could be disconnected and make it almost impossible to steal the car short of towing it away? I was thinking of having a well hidden switch(es) that would open/close the circuit that the wire makes. When opened, maybe the engine won't start or won't rev over 100 rpm, or maybe the tranny won't shift out of Park... or whatever obstacle you can think of that a particular wire could present to a thief.

Obviously this would need to be something safe, and the wire(s) would go through a redundant path, so if a switch failed then there would be 1 or 2 other lines (thus 2 or 3 switches total) that would complete the circuit. Probably have circuit-fail warning lights to let you know when a switch isn't working.

My inspiration is from someone I knew who had an aftermarket engine controller that he could control with a Palm PDA; when he was going to be away from his car he just set the rev limiter to 100 rpm and took his Palm with him. Worked beautifully!

So what are the expert's thoughts on this? Feasible? If so, which wires would you recommend to do a good job and still be safe (as safe as this kind of thing can be)?

[This message has been edited by quijybo (edited 06-11-2007).]

Pretty much, not any one sensor would work very well, I would probley just switch the ground on the fuel pump, should be fairly impossible to run the car without fuel.

I have used a toggle switch on my fuel pump in my Nova. It works pretty well, but only drawback is occasionally they can still get the car started, just can't go very far. I have found my Nova several hundred feet from where I parked it before.

Is there any benefit to interrupting any circuits on the tranny controller? Since it's an electronically controlled tranny, can you keep it from being shifted out of Park despite the shifter handle position?

The fuel pump sounds like a good way to go, too. 99% of my parking locations are at least several hundred yards from a busy street, so it would probably just be blocking a side street or parking lot lane.

Just use the fuel pump power line. I just pull the fuel pump fuse myself, kind of like an extra key. A theif is not going to have a clue why the car isnt running much less go searching around for missing fuses.

The kicker to the fuel pump fuse, the fuel rail will hold pressure and enough gas to run for a few seconds. So if someone did start it they would have about enough time to get out of the parking spot and into the road with it. Now hes stuck dead in the middle of the road with a car that was running fine and just mysteriously dies, you think hes gonna wanna spend a bunch of time out in the open, already attracting attention, trying to figure out why?

quote Originally posted by quijybo: Is there any benefit to interrupting any circuits on the tranny controller? Since it's an electronically controlled tranny, can you keep it from being shifted out of Park despite the shifter handle position?

Nope, you will just make the transmission go into a limp mode, which would make for some fun shifting.

Just kill ( switch) the power to the coil pack.

Hidden batt kill switch

You are over thinking it.

quote Originally posted by revin: Just kill ( switch) the power to the coil pack. Hidden batt kill switch You are over thinking it.

Yeah, I tend to do that. It does help to pay the bills, though.

Can't cut the battery, but what will the kill switch on the coil pack do? I'm definitely going with the fuel pump switch, but additional safety methods are always nice.

Thanks everyone!

no coil pack = no spark, IMO the safest way to switch the motor because if you accidently hit the kill at wot or somthing, you would be alot safter running out of spark instead of running low on fuel creating a lean condition.

Hmm, good point. Thank you all for the help.

Thats a good idea, but a security kill switch isnt going to be anywhere you could bump it. Having it mounted to the bottom of the dash is going to defeat the purpose, lol.

OR
Wire the switch into the door lock mech. ( providing that you have electric door locks)
Then when you lock the doors, you enable the "kill switch.

OR

Take the main wire from the key switch and add the kill from there.

I personally wired up a hidden toggle switch under the shifter boot that powers the injectors.