Hello
I have a 2004 TD6 Vogue, I had some ignition issues such as the ignition coming on and off by itself, thesE symptoms occured after it sat for about 5 days. I fitted a new ignition switch and it won't crank, not even a click from the starter. If I put the old one in, then it starts straight away. I've left the negative off the battery for a short while before reconnecting it, I'm going to leave it disconnected overnight and see what happens. I will probably put the old switch back in again to drive it again. It is very strange, anyone have any ideas.

Thanks

Check the continuity of the new switch
Could be faulty 2007 Vogue TDV8 in Zermatt Silver with Charcoal

Do you know pins I need to check continuity through.
Thanks

No but you should be able to work it out from the loom. One will be a common ground. The others will be the various live feeds. They should all give a value through the common ground. 2007 Vogue TDV8 in Zermatt Silver with Charcoal

So checked all the connections in both positions of ignition, all are the same except for the black and yellow wire going to the EWS unit. On the new switch, when turning to crank it over, there's a reading of 0.13 v and drops to 0, and on the old one it goes to around 12v before going back to 0.

I haven't touched one of these for ages but aren't they coded to the car? Hence why your immobiliser won't allow the starter to engage?...

From what I've read, the ring antenna is above the switch and that's what sends the key info to the EWS. So this should theoretically work without any coding.

So, exactly what have you changed?

Just the ignition switch.

The metal barrel or the electrical black box?

If you've replaced the barrel, what key are you using?

So just changed the electrical box, I opened it up and found some black residue on pin 8 which is for the EWS, I was cleaning it as I was replying to you. Just installed it in the car and it's running perfectly now. The residue was only on the one contact, that's why the ignition was working but it felt as if the immobiliser was not allowing the engine to turn over.

 2007 Vogue TDV8 in Zermatt Silver with Charcoal

Great news