Push Button Start on 97 V8 Esprit

[Wanderor Cross]

I hope this is the right section, so my Ignition Cylinder locked in the off position and it seems the local shops here cannot help plus to remove it you need to be able to turn the cylinder...

So I decided to try a Push to start button set up but I am having an issue. I can get the starter to work but the car won't actually start it just turns over. But if I use the stock switch with the housing pulled off and a screw driver it fires right up...

I was following the guide someone else used for an S2000 Button on an S3 but mine seems a little different.

http://www.lotusespritworld.com/EGuides/EModifications/StarterButton.html
With mine there are 4 wires but one of them I am not sure what to make of it, I thought it was a ground but I tried grounding it and that did not work so I tried applying power and that did not work.
From what I figured out this is the wiring, 1 is Constant Power, 1 is Accessory, 1 is Ignition and then the 4th I just don't know... I testing it and it seems to OHM out to a ground as I said and turning the switch it never seems to get voltage even when started so I have no idea what to make of it but this one wire seems to be the problem with getting the car to run.

The guide talks about 3 wires so I am a little confused on how to make this work.

[Escape]

4-wires are used on most ignition switches. Looking at the V8 diagrams, you should have:
- permanent 12V (NR)
- accessories like radio (KA), position I & II
- ignition (W), position II & III
- starter (WR), position III

To get the engine running, you need power to W to feed the ECU, coils etc and power to WR to activate the starter motor (through a relay). So if you want to fit a starter button, you still need an ignition switch with a working position II to power all the car's systems. And as a side effect the radio would not turn off while cranking. Which might be annoying, but is standard procedure to limit power use during cranking. Earlier Esprits even had a start drop out relay to cut power to the fans etc while cranking.

Sounds like your best bet is to get familiar with the wiring diagram for a 97 V8.

Filip

 

 

[Wanderor Cross]

Sadly I do not have the diagram but when I tried powering that last wire I ran into the issue of it not working.

I would not mind getting my Ignition cylinder fixed but since i am in the states it seems I am SOL for anyone being able to.

[Yellow and Green]

 

You aren't going to get very far without the wiring diagram and a lot of good guessing.  I'll try to PM you the wiring diagram after posting this.

But before you go through all this trouble, why not just order an ignition switch from the vendors and replace it?  It only takes about 10 minutes once you have the right part.

I built a harness to accomplish what you are trying to do while I was waiting for the parts to ship.  As the previous poster mentioned, you need two switches: one constant contact to turn on all the accessory power, and a second momentary switch to turn over the starter.  It's worth noting that neither of these will bypass the immobilizer, so you'll need to operate that as normal.

You can build a harness with spade connectors to avoid hacking up any wiring if you still choose to go that route.

[Escape]

Here you go. 🙂
Just ask if you need any other diagrams.

V8 ignition wiring.pdf

[Wanderor Cross]

On 24/12/2021 at 09:47, Yellow and Green said:

 

You aren't going to get very far without the wiring diagram and a lot of good guessing.  I'll try to PM you the wiring diagram after posting this.

But before you go through all this trouble, why not just order an ignition switch from the vendors and replace it?  It only takes about 10 minutes once you have the right part.

I built a harness to accomplish what you are trying to do while I was waiting for the parts to ship.  As the previous poster mentioned, you need two switches: one constant contact to turn on all the accessory power, and a second momentary switch to turn over the starter.  It's worth noting that neither of these will bypass the immobilizer, so you'll need to operate that as normal.

You can build a harness with spade connectors to avoid hacking up any wiring if you still choose to go that route.

And here I thought these didn't have an immobilizer that must be the issue I am running into since the starter turns over when I push the button it just can't fire.

Thank you for the harness layout that's perfect!!

[Wanderor Cross]

So this just came in the mail, let's see how it looks installed.

[Wanderor Cross]

Alright so it took me awhile as I had to figure out the wiring but I finally got it done but now I need another switch and pigtail for the cluster so I can make my kill switch set up more factory instead of a switch I just have hidden under the dash.

 

For now though everything works correctly and I really like it.

 

 

[mike_sekinger]

Nice job.  Very similar positioning here.