Please check this relay plan

Hi all,

Many of you may have heard of the car mod 'push button start' usually using the honda S2000 button.

I don't have that kind of cash - so am doing it cheaper...

Planning to use a 12V 30A SPDT relay set up as follows, with the following wiring guide.

GREEN/ YELLOW wire - main ignition wire

ORANGE / Grey - Engine starter wire (when current flows from the GREEN/ YELLOW wire into this one - the engine turns over)

This was how i planned to wire the relay in.

86 - Earth

85 - Positive with a push button switch in line

30 - GREEN/ YELLOW

87a - GREEN/ YELLOW

87 - ORANGE / Grey

My understanding was that when the button wasn't depressed and the coil charged, the current would just flow through 30 to 87a and the wire would act as normal, but when the button was pressed on 85, it would let current run into the coil, charge it and make current flow from 30 into 87 acting as the final turn of the key on the ignition. then once engine started and i took my finger off the button, it would drop back to 87a.

Have i got this all wrong? or would this work as i understand it to?

Any comment would be greatly appreciated. Thanks.

I would try to use an Accesory wire instead of an ignition wire, just to be safer. you have the wiring correct, and the wiring would be the same for the acc. wire. remember the wire connected to 87a will loose power when the button is depressed.

Hi,

Yes its of a Ford Focus UK Spec Zetec.

Losing power through 87a won't be a problem when the coil is charged as it'll just be bridging 30 to 87 in effect 'hot wiring'

This will be alright won't it?