Classic Car Security
This information was originally published as an article in TRaction the club magazine of the Triumph TR Register and although biassed towards the sidescreen Triumph TR's hopefully it will be useful to owners of other marques.
This information has been gathered from personal experience and is believed to be accurate but there is no guarantee that this is the case. Anyone using this information does so on the understanding that its use is completely at their own risk and that no legal liability of any kind will be accepted by the author for errors or ommisions or consequential damage to persons or possessions. Prospective users should make their own considered judgement or seek specialist advice as to the accuracy or otherwise of any statements made before using this information in any way. The procedures detailed below include modifications to both the fuel supply and the cars electrical system if you are not competent in either of these areas you are advised to seek expert help.
The recent increase in Classic car thefts prompted me to look at ways to protect my car from the villains. Modern cars are now without exception factory fitted with comprehensive security. Many of these use immobilisers that are embedded in the ECU (Electronic Control Unit or computer) that controls the engine etc. so are extremely difficult to bypass. This is probably one reason why Classics are now a target for criminals and as values increase there is a ready market for spares that are easily disposed of. Classic cars including side screen TR’s are basically very simple in construction both mechanically and electrically
with most parts being very accessible, a modern stand-alone electronic immobiliser is thus not appropriate as its presence and function can easily be spotted and bypassed. So what are the options?
1. A mechanical device can be used to clamp a wheel, lock the steering, gearstick,
handbrake or foot pedals
2. The steering wheel may be removed
3. The electrics can be disabled in some way
4. The fuel supply can be cut off
5. A tracking device can be fitted
6. A paging device can be fitted
If your car is targeted by a criminal it may be a random opportunist theft or could be stolen to order. If the latter they are likely to have done their homework and will have a much greater chance of success. All methods of prevention are really playing for time so the longer the methods take to overcome the best chance you have of maintaining ownership. A determined thief may actually be prepared to winch the car into a van or on to a trailer so unless they are caught in the act many of the above deterrents will prove useless.
Mechanical devices such as steering wheel locks take seconds for a criminal to overcome so offer little protection. Devices that lock the pedals to the floor are much better but I have only ever seen these designed for commercial vans. Wheel clamps do seem fairly effective but are generally far too bulky to be carried in a TR. Removing the steering wheel is a good deterrent
as even seasoned thieves are unlikely to carry appropriate replacements.
A battery cut off switch is very useful for isolating the supply but a thief intent on action will no doubt carry keys and can in any case easily short out the switch with a simple cable. Likewise a simple hidden switch in the ignition circuit is easily bypassed by wiring the ignition circuit direct to the battery.
Removing the rotor arm when leaving the vehicle will deter many opportunist thieves but a professional stealing to order will no doubt carry a spare.
Cutting the fuel supply by solenoid valve and a hidden switch would not prevent the car being started but would soon cause the engine to stall, a car stopping unexpectedly would no doubt unnerve most thieves into abandoning the car.
A tracking device is claimed to be the most effective solution in that the stolen vehicle can be tracked continually, I am not convinced that a tracker would still function if the car was winched into a steel bodied van. Trackers are also very costly both to buy and for the tracking service.
A paging device would seem to offer the big advantage that as soon as the vehicle is being interfered with the owner is warned by a bleeper. Provided the owner is within about a half a mile of the car this should be successful. For cars stolen at car rallies etc. this seems a good solution.
After considering the above I decided to adopt the following measures:
A) Install a battery isolation switch
B) Install a fuel cut off valve
C) Install a pager
Battery Isolation Switch
More for peace of mind rather than a deterrent. Being able to fully isolate all electrics is a bonus to prevent potential electrical faults while parked. The nearside blanking plate was a very convenient position for the switch and avoided hacking holes in the shiny bulkhead. It is close to the battery and the key is conveniently positioned under the glove box for isolation.
Fuel Shut Off Solenoid Valve
The fuel line from the tank to the carburettors runs through the nearside chassis rails. The shut off valve can be partially hidden by mounting within the U-section and making a simple cover as shown. Unless the car is placed on an inspection ramp it is unlikely to be noticed, even by looking under the vehicle. The solenoid valve is normally closed and requires 12 volts to open the valve and allow fuel to flow. This can be achieved by a small hidden switch fed from the ignition supply. The particular valve chosen has a manual bypass lever, so if for some reason the switch or the supply fails then the fuel supply may be manually turned on. As the lever is well hidden within the chassis rail, unless you are aware it would never be noticed and would require the car to be jacked up to reach the lever. During tests the car started normally but cuts out approximately after about 1 minutes running. When the valve is activated again the car starts almost immediately. I believe the closed valve causes a partial vacuum to prevent the petrol pump working as the fuel bowl is still full of petrol when the engine stops.
An important point, do not use ordinary jubilee clips to secure fuel pipe, the special fuel pipe
clips provide a much more efficient and safer clamp.
Fuel Shut off Valve
The Shut-Off Valve Shown Mounted in the Chassis Rail
A fuel pipe Clip is shown below a conventional Jubilee clip
A basic aluminium cover was fabricated from thin gauge material and secured to the underside of the chassis with two self tappers. If the solenoid valve failed it would be a simple matter to bend the cover and operate the manual tap. A sub-miniature toggle switch was fitted in a hidden but convenient place, but to ensure it was not inadvertently switched off I made up a simple metal guard.
Miniature Toggle Switch with Simple Metal Guard
This fairly simple method of protection has proved reliable and given a degree of confidence when leaving the car.
One economically priced alarm/immobiliser security system the Sniper X2 includes a pager as standard. The system comprises: A main control unit, shock sensor, siren, flashing Light Emitting diode (LED) and paging antenna all for £50. The Sniper X2 is a comprehensive security system but only the pager and shock sensor were of interest for this application so most of the connections were not used, the redundant cables being trimmed for neatness. The Sniper X2 is designed for –ve (negative) earth systems but is easily adapted to the TR’s +ve (positive) earth. I decided to use two trigger sources for the pager:
1.The supplied shock sensor
If a potential thief opens a door or sits on a seat the vibration is enough to cause the shock sensor to trigger the alarm on the pager. The sensitivity may be adjusted to avoid false triggering. Also if the ignition is switched on, the alarm is again triggered.
The kit also includes a switch for boot or bonnet should this be thought necessary. A flashing LED is supplied to indicate alarm status. I mounted all the items using Velcro, the control box and shock sensor under the occasional rear seat and the antenna unit on the back rail under the tonneau cover.
The Sniper-2 Antenna Unit Mounted on the Tonneau rail
The Sniper-X2 Shock Sensor
The Sniper-X2 system is designed for negative earth vehicles where the permanent and ignition supplies would be positive. As the TR3A is positive earth, the Snipers earth lead (black) is connected to the TR’s permanent live feed and the main positive supply lead (red) is connected to the TR’s chassis earth. The unit requires a positive ignition feed to trigger the alarm so a relay is used to provide this from the TR’s negative ignition feed:
A Simple Circuit using a 12 Volt Relay Provides a Positive Ignition Trigger from a Positive Earth System
The pager is claimed to have a range up to ½ mile in open ground, but through buildings or difficult terrain this range would be reduced. During tests it certainly functioned very well on open ground.
Battery isolator: Polevolt, www.polevolt.co.uk
Fuel hose and clips: Halfords, www.halfords.com
Fuel Cut Off Valve: Tinley Tech Limited, www.tinleytech.co.uk
Pager unit: In Car Stuff, www.in-car-stuff.com
Sub-miniature toggle switch, Maplin Electronics, www.maplin.co.uk