Kill Switch on Starter Solenoid

[Kitimoto Wayne]

Hi All,

I have searched the forum for the above topic and was not able to find anything in regards to this. Can somebody direct me to the right topic if there is one else can someone give me advice on installing a kill switch for the purposes of additional security to prevent theft, which we have a massive issue with here in SA.

I would like to put a switch circuit on the starter solenoid of my 2010 Caddy Maxi 1.9 tdi using a reed switch with relay module. I have been advised that the potential to damage the vehicle computer is present, hence the need to get some solid advice.

TIA.

Wayne

 

[DivineChaos]

Hi All,

I have searched the forum for the above topic and was not able to find anything in regards to this. Can somebody direct me to the right topic if there is one else can someone give me advice on installing a kill switch for the purposes of additional security to prevent theft, which we have a massive issue with here in SA.

I would like to put a switch circuit on the starter solenoid of my 2010 Caddy Maxi 1.9 tdi using a reed switch with relay module. I have been advised that the potential to damage the vehicle computer is present, hence the need to get some solid advice.

TIA.

Wayne

It's not going to damage the computer. When looking at the starter there is one small wire. This is the wire that activated the solenoid. Route that wire through your Killswitch. Make sure it's hidden.

 

[burpod]

Search for this more. Imo it's better to put a switch to interrupt ground to relay 109 so ECU is killed, and then you don't introduce a switch in a higher amp circuit

 

[Mozambiquer]

I would put it on the ecm relay circuit as well, that way it'll shut it all down. Putting it on the starter wire is really easy to bypass, as you can easily hot wire the starter, even without opening the bonnet. That engine should be a PD or common rail, which you can't just hot wire to the shutoff solenoid like the ve pump TDI could be.
Are you setting it up with the hijack security system? Or a completely separate system?

 

[Kitimoto Wayne]

I would put it on the ecm relay circuit as well, that way it'll shut it all down. Putting it on the starter wire is really easy to bypass, as you can easily hot wire the starter, even without opening the bonnet. That engine should be a PD or common rail, which you can't just hot wire to the shutoff solenoid like the ve pump TDI could be.
Are you setting it up with the hijack security system? Or a completely separate system?

Search for this more. Imo it's better to put a switch to interrupt ground to relay 109 so ECU is killed, and then you don't introduce a switch in a higher amp circuit

The switch circuit design I have in mind is a momentary switch. That's why I want to put it on the starter solenoid. I will use a reed switch with a 20amp relay. The reason for this is two fold. Because the reed switch is activated with a magnet, it will be easy enough to conceal the switch behind a panel in the cabin. And secondly because it is a temporary switch the circuit is broken once you remove the magnet but the engine will keep running. At least this is my plan. If it will not work please let me know. Also, is there not a low current wire on the starter solenoid. I would have though that the 20amp relay would have been sufficient.

You thoughts on this is greatly appreciated.

 

[Mozambiquer]

The switch circuit design I have in mind is a momentary switch. That's why I want to put it on the starter solenoid. I will use a reed switch with a 20amp relay. The reason for this is two fold. Because the reed switch is activated with a magnet, it will be easy enough to conceal the switch behind a panel in the cabin. And secondly because it is a temporary switch the circuit is broken once you remove the magnet but the engine will keep running. At least this is my plan. If it will not work please let me know. Also, is there not a low current wire on the starter solenoid. I would have though that the 20amp relay would have been sufficient.

You thoughts on this is greatly appreciated.

That could work, though it would be ineffective against many criminals as they often will hot wire the car to get it started. It will work to help prevent low level thieves from stealing your keys and driving off though.

 

[Kitimoto Wayne]

That could work, though it would be ineffective against many criminals as they often will hot wire the car to get it started. It will work to help prevent low level thieves from stealing your keys and driving off though.

Ok. I am confused. If the starter solenoid is disabled, how will hot wiring at the ignition bypass the solenoid.

 

[Mozambiquer]

Ok. I am confused. If the starter solenoid is disabled, how will hot wiring at the ignition bypass the solenoid.

The ignition isn't the only place you can hot wire it. It's really easy to access the starter to hot wire it right there.

 

[DivineChaos]

The switch circuit design I have in mind is a momentary switch. That's why I want to put it on the starter solenoid. I will use a reed switch with a 20amp relay. The reason for this is two fold. Because the reed switch is activated with a magnet, it will be easy enough to conceal the switch behind a panel in the cabin. And secondly because it is a temporary switch the circuit is broken once you remove the magnet but the engine will keep running. At least this is my plan. If it will not work please let me know. Also, is there not a low current wire on the starter solenoid. I would have though that the 20amp relay would have been sufficient.

You thoughts on this is greatly appreciated.

On your starter there is a large and small wire. Interrupt the small one.

 

[DivineChaos]

That could work, though it would be ineffective against many criminals as they often will hot wire the car to get it started. It will work to help prevent low level thieves from stealing your keys and driving off though.

True. They'd see the switch unless it's hidden well.

 

[Kitimoto Wayne]

The switch circuit design I have in mind is a momentary switch. That's why I want to put it on the starter solenoid. I will use a reed switch with a 20amp relay. The reason for this is two fold. Because the reed switch is activated with a magnet, it will be easy enough to conceal the switch behind a panel in the cabin. And secondly because it is a temporary switch the circuit is broken once you remove the magnet but the engine will keep running. At least this is my plan. If it will not work please let me know. Also, is there not a low current wire on the starter solenoid. I would have though that the 20amp relay would have been sufficient.

You thoughts on this is greatly appreciated.

If I switch ground on 109 relay, can it be a momentary switch circuit?

 

[DivineChaos]

If I switch ground on 109 relay, can it be a momentary switch circuit?

No. Has to be on or off. It's the power to the main computer. Can't be a momentary switch