ignition switch

my s3 2.3 diesel had a non standard ignition switch that had been put in the dash, I have bought a new - supposedly genuine oem from lr series - with the steering lock to go back on the column.

however, when I connect the wires as per the manual,

1 brown and red (my wire is all red)
2 white and red
3 white
4 brown

the engine turns over as soon as the battery is connected. I tried reversing the red and brown wires, the engine didn't turn when I connected the battery but it did as soon as I turned the key to position one.

is it likely the new switch isn't wired properly?

My drawing shows white on 2 ,White red on 3 ,two browns on 1, but mine was originally petrol ,
Diesel drawing shows as you have it .Try connecting just the brown which should be the supply , then just touch the white on other contacts with the key in off position none should put alternator light on then try each postion to see when they are live.
Not sure if ignition is position 1 or two on a diesel ie 1 glow plugs or ignition.
when you go to the expected starter motor position where does the key drop back to.

thx for the reply

mine was originally petrol going off the chassis number but was diesel when I got it and showed as diesel on the v5 so I shall try out your settings and see if that's it and if not just fiddle with the wires as you suggest.

the old switch doesn't have a position marker, it is just stuck thru the dash with a nut on it, you turn it one position to get power then turn and hold for the glow plugs then turn again to start and it returns to position one when you let go.

the new one does the same but has the proper position markers

hopefully it will stop ****ing down soon

seem to have got it working now, after a bit of fiddling, looks like whoever converted it to diesel or put the non standard ignition switch in didn't stick to the stock colour scheme.

1 red
2 white
3 brown
4 white and red

also works with red and brown swapped, but the first diesel wiring diagram - assuming I am reading it right - seems to go to the glo plugs for terminal 1. The red lead is the only one I can successfully trace, it goes through the bulkhead to that resistor/spring on the bulkhead engine bay side and then to the glow plugs (or what I think are the plugs, one on each cylinder below the injectors). all the others disappear into the taped up loom and don't seem to come out so I wouldn't be surprised if they are connected to a different colour wire in there. Certainly ain't gonna cut the tape off to find out

So I shall put the red on 1. Seems to fire up fractionally quicker with the red on 3 though

You could do with glamorous assistant to hold key over whilst you check power to glow plugs. Mine had been buggered about with, not sure what the eventual wiring was when it finally got working. The advantage of an auto electrician mate...........

I could do with a glamourous assistant for most things

I think life would generally be more pleasant with one and background music.

think I might actually have figured this out once and for all, seems there are a few positions of the wires that will start the car, but as the rest of the electrics weren't working I hadn't realised that what I thought was right wasn't.

Using the brown as the power feed (now having tracked it through the loom as it went in but never came out because it changed to red whilst it was in there) as it goes to the same terminal on the starter as the battery positive lead goes to and is the only one of the leads that is actually live when the battery is connected. Red and white (Changes to black and white in the loom) goes to the other terminal on the starter setup. Red is glow plugs and white goes to the voltage regulator and charge light.

My ignition actually has 5 terminals, 1 and 5 being next to each other. So I put the feed on terminal one to start with no other wires on the switch, then I tested each terminal in the off position to see if they were live then moved through the key positions.

Power feed can't go on terminal 1 as no other terminals are live in key positions 3 and 4.
Can't go on 2 as terminal 4 is live when the ignition is off. Can't go in position 4 either because other terminals are live when the ignition is off.

Having the feed on position 5 or position 3 gives the same results (apart from which terminal is always live obviously)

Off - no other terminals live
key 1 - no other terminals live
key 2 - terminals 1,3 and 5 live
key 3 - terminals 2,3 and 5 live
key 4 - terminals 2,3,4 and 5 live

As the truck was originally petrol according to the circuit diagram the feed was the first terminal (5 for me) so I am putting brown on 5.

As terminal 2 is only live in key positions 3 and 4 i.e. heater plugs and start position I will put red on 2 as it goes to the glo plug resistor on the bulkhead.

Going to put the charge light and voltage regulator on terminal 3 as this is live when the key has fallen back after starting.

Finally red and white on 4 as this goes to the starter and terminal 4 is only live in the last key position i.e. where you turn it to to start the vehicle.

Does this sound like a plan