help with diy immobiliser

That circuit has been used for over 20 years. It is one of the most stable, and theft deterrent and simple circuits to apply. I use something similar in my vehicles. What part don't you understand? Please be specific, so as we can help you. Regards EVIL Teken . . .

1life2live wrote: I don't understand the dpdt relay.

As A starter I would urge you to take a few moments to read over all the previous topics / threads that are in this forum. Also any other sites which pertains to relays in general. This will explain the general operating structures of a relay, and give you a basic understanding of them and how they function. Each manufacture will have different pin outs, but all will function in the same manner, only the voltage / current rating will differ, this applies to electromechanical relays only.

1life2live wrote: it has 8 prongs, each one numbered 1-8.

At the top of the picture which you have included in your link. The two contacts are the coil. From, the wiring provided the top would be pin +86 which is the positive source. The pin below, is pin -85. Both are could be labeled any number from any manufacure so, you will have to follow the spec sheet that comes with the relay. All you need to know is that one end is the coil which requires a (+) positive source, and the other end requires a (-) negative source to activate the relay.

1life2live wrote: I don't understand based on the diagram where the 12 volt fused supply should connect in relationship to the dpdt relay.

The 12 volts fused power supply connects to the top of the coil, which will mean that is automaticly the positive side of the coil. The other positive lead you will notice is attached to the bottom portion, which is the normally closed position of the relay.

1life2live wrote: The diagram uses arrows what does that mean?

The arrow indicates / means that is the N.C. or normally closed position or at rest position while not energised.

1life2live wrote: I'm totally loss.

You are not lost. You simply do not know. If you were completely lost, you would not be here asking me this question. So keep going . . .

1life2live wrote: Where should the reed switch connect to on the relay,

As it appears on the image file you have supplied, one side of the reed switch is attached to the coil side of the relay. The other end is simply connected to ground (-) / the vehicles chassis frame. This completes the circuit / activates it / turns it on.

1life2live wrote: where should the push button connect to on the relay.

One end of the push button will connect to the *N.O* Normally Open side of the relay, the other end connects to chassis ground (-) Regards EVIL Teken . . .

The remainder of the schematic is pretty straight forward. If you do not know what else goes where, please ask. Regards EVIL Teken . . .