Kill Switch for 86 Carrera

[notfarnow]

Thanks to pelican parts, my dad has an 86 Carrera Cab on the way from Virginia. I found the car in the classifieds here, and got some great PPI advice. Other than a couple niggly little issues, the car checked out great.

There is no way the car would have been bought without this great resource. Thanks!

Anyhow, dad's insurance says we need an anti-theft device installed. I hate the idea of some crap-tastic aftermarket alarm, and thought a simple hidden kill switch would be the ticket.

What should we wire it to? fuel pump? DME?

[rouxroux]

For a quick & easy solution that will probably satisfy that need, how about one of the "screw-type" battery disconnects? They're usually under $10.

[notfarnow]

Originally posted by rouxroux
For a quick & easy solution that will probably satisfy that need, how about one of the "screw-type" battery disconnects? They're usually under $10.

Thanks for the reply!

That would be quick & easy, but I don't know if that would be sufficient for the insurance co. Plus, I can guarantee that neither dad or his wife will want to pop the hood to dsconnect the battery when they're downtown.

[mschuep]

are you sure it doesn't have the factory alarm installed?

[notfarnow]

Originally posted by mschuep
are you sure it doesn't have the factory alarm installed?

According to the PO, it has no OE anti-theft or alarm.

[fitchn]

I've installed a kill switch in my fuel pump circuit in my SC, just hijack the wires going into a fuse box and run some wires into the passenger compartment to a clever spot where you can mount a switch. With the fuel pump circuit disconnected the car will turn over but won't fire so I imagine any thief trying to hot wire it would either burn out the starter or kill the battery.

[javadog]

One of the tricks some people use is to buy a factory switch for an option the car doesn't have and install it in the dash in the factory location. Something like a headlight washer switch, or some such. Then you can run wiring from the switch to accomodate whatever anti-theft measure you want. Convenient to use and the average thief is unlikely to notice it, as it doesn't look like something added later and an attempt at hiding something.

Chuck Stoddard once gave a description of a simple anti-theft wiring modification for the 911SC-era cars. It was originally posted in Pano and then re-printed in the Up-Fixen series of books. If my memory is any good, the neat thing was it would allow the car to start, then die. The theory was the thief would assume there was something wrong with the car and go elsewhere.

I don't recall the details but perhaps you could look it up and get a few ideas. Perhaps it could be adapted to a later car.

JR

[notfarnow]

Great info, thanks folks.

I especially like the idea of "hijaking" a line from the fuse panel, and using a factory switch.

[boostfix]

Originally posted by rouxroux
For a quick & easy solution that will probably satisfy that need, how about one of the "screw-type" battery disconnects? They're usually under $10.

here is a remote version of this. Hit the wireless remote to disconnect your battery

http://www.canadiantire.ca/browse/product_detail.jsp?PRODUCT%3C%3Eprd_id=84552444329 4641&FOLDER%3C%3Efolder_id=1408474396672395&bmUID=1171059093362

[notfarnow]

So I'm headed up to Montreal in two weeks to get dad's car "prepped" for the season... oil change, fiddle with the heater controls and a few other small items.

Top of the list is installing a kill switch; he can't get theft insurance until one is installed.

On an 86 Carrera, which circuit is best to interupt? I could run the switch to a ground, but what component should be disabled by the switch?

I'm thinking just the coil, would that be easiest?

[mschuep]

The ground wire that runs off of the DME main/fuel pump relay under the drivers seat next to the ECM is a good interruption point. IIRC, it is a brown wire off of terminal 85.

The wire (along with others) runs from the relay, over to the drivers side, and then back toward the engine bay. When engaged, the car will crank but not start. Where you run the wiring and put the switch is up to you. If you want more info or wiring diagrams shoot me an email.

[Porsche_monkey]

A battery kill switch will lose all your radio pre-sets. Kill the ignition system or the fuel pump with a switch inside the car. Or add the old style high beam switch on the floor.

[notfarnow]

Originally posted by mschuep
The ground wire that runs off of the DME main/fuel pump relay under the drivers seat next to the ECM is a good interruption point. IIRC, it is a brown wire off of terminal 85.

The wire (along with others) runs from the relay, over to the drivers side, and then back toward the engine bay. When engaged, the car will crank but not start. Where you run the wiring and put the switch is up to you. If you want more info or wiring diagrams shoot me an email.

Bingo! This is exactly what I was looking for, thanks so much!

[mschuep]

Glad I could help...my only advice would be to take your time soldering the switch and connections, as this is obviously something that could strand you somewhere down the road. Good Luck!

[notfarnow]

Another great tip... left to my own devices I probably would have used crimp connections.

Thanks!

[stomachmonkey]

PO may not have known about factory alarm.

Open drivers door, is there a small lock cylinder in the door?

Scott

[javadog]

Originally posted by notfarnow
Another great tip... left to my own devices I probably would have used crimp connections.

Thanks!

There's actually nothing wrong with a properly done crimp connection. I have a friend who runs a defense subcontracting company that makes wiring harnesses for subs, navy ships and missiles and soldered joints are apparently not common in their products. I am no expert on electrical wiring but I am led to believe it is easier to screw up a soldered joint. They may be less vibration resistant than a crimped connection.

Just use connectors that are better than the crap that is sold in the auto parts stores and use a good quality crimper, designed for the specific connector you plan to use.

JR

[Porsche_monkey]

If crimped connectors didn't work, then most cars would ever start.

[DW SD]

If you look at the wiring diagram, there are a 12V leads from the ignition switch which turns on:
1. the ignition
OR
2. the starter relay

If you intercept either one and put a simple, low current switch in line that is hidden under the dash, you don't have to change the factory wiring and should prevent your car from starting.

I'm thinking the yellow wire for the starter relay would be good. It would seem as if the battery is too dead to crank.

Find some nice crimp connectors and use shrink wrap tubing to make things clean. The important part about using crimp connectors is the right crimping tool. Search the internet a bit and you'll find a nice tool, which forms a factory-style crimp.

This website has the wiring diagrams for the entire car and ignition switch.

Doug

[rnln]

Originally posted by mschuep
The ground wire that runs off of the DME main/fuel pump relay under the drivers seat next to the ECM is a good interruption point. IIRC, it is a brown wire off of terminal 85.

The wire (along with others) runs from the relay, over to the drivers side, and then back toward the engine bay. When engaged, the car will crank but not start. Where you run the wiring and put the switch is up to you. If you want more info or wiring diagrams shoot me an email.

This is exaxtly what I've been thinking to do. May I ask what kind of current rating on this wire? The purpose is for selecting the switch. I don't want to have a too small switch installed and get burned.
Thanks.