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Push button ignition and Start
AndyGaskell - 28/1/18 at 10:39 AM

Hi all,

Im doing away with the key barrel altogether on my sierra based kit car and wondered if anyone has any knowledge of the wiring so they can double check my wiring

So this is my plan,

Ignition switch

Take 12v ignition live to the live side of the switch (red)
Take the Aux1 Ignition cable from key barrel to Switched side of switch (black/yellow)
Take the Aux2 Ignition cable from key barrel and link to same Aux 1 side of the switch (yellow)

Start switch

Take 12v ignition live to the live side of switch (red)
Take the Starter solenoid to other side of switch (black/blue)

Is this ok to do or should i be using 2x Switches for ignition to keep the 2 stages and then the start switch?

The car is a track car and the security isnt an issue as other measures have been put in place so no need to worry about the key.


ReMan - 28/1/18 at 11:08 AM

Done know the colours but in principle yes that’s what you need to do


tims31 - 28/1/18 at 03:56 PM

I think the Black/Yellow is your switched live and the yellow is just for AUX Items so you should only need a switch for the black/yellow and the button for the Black/Blue starter.

If your removing the ignition barrel you may have an issue with the steering lock?


AndyGaskell - 28/1/18 at 11:42 PM

I have removed the steering lock

So update, the start switch is fine but the ignition switch as wired above works great first time but when you break the switch it doesnt break the supply. I guess its getting a feed back through the switched supply.

So my second revision was:

One ignition switch

Ignition live to the switch (red)
Live out of the switch switches 2 relays
Relay one supplys 12v to ignition outs (black/yellow)
Relay two supplys 12v to aux out (yellow)

Starter switch as was.

I will be reconfiguring to this tomorrow but i dont see why it wont work in this way as it in theory acts as the key barrel ignition does but with relays


theduck - 29/1/18 at 08:14 AM

Sounds like it should work fine. Please tell me you have fitted an immobiliser and some kind of mechanical theft deterrent though? I have a similar setup to you and have an immobiliser and a removeable steering wheel.


AndyGaskell - 29/1/18 at 08:32 AM

Indid mention that measures had been put in place in the original post, but yes mine has an immobiliser, removable steering wheel and is in a secure garage


theduck - 29/1/18 at 08:50 AM

Oops missed that. Sorry, tired eyes this morning!


ken555 - 29/1/18 at 11:49 AM

You might want to put the fuel pump on a separate switch.

But I have the same set up.

FIA kill switch powers up the first relay. So things like hazard lights, sidelights
Switch powers up ignition/ECU circuits relay
Switch 2 powers up fuel pump relay.
Button powers Starter