Help with ignition switch wiring on a 300tdi

[Davecrx]

Hi

I need a bit of help finding the wiring that goes to and from the ignition switch...

I'm wanting to wire up a switch to turn on my ignition and push button to crank the engine

Sounds odd i know but i've got a 300tdi disco that has had the ignition switch taken off but my trouble is i've got two plugs a red and black plug which don't have the colours i'm looking for. (see pic)

The Red plug has the following wires:

purple, black, light green, green, and gray.

The Black plug has two purple/black and two purple/white

I also have found two wires, a brown and a green. when i joined them together i heard a click in the passenger foot well

Life would be a lot easier if i had a good wiring diagram for the 300 disco, i've only got a diagram for a 300tdi defender.

[Davecrx]

Little update....

The brown and green when connected together puts +12v to my radio.

The red plug i'm thinking is for the air bag if it had one.

The black plug is for the ignition switch light.

I've found out that i need to find a white, white/red and yellow wire but can't seem to find them around the steering column.

Could someone tell me the rough location of these wires.

Thanks Dave

[mscowley]

Have look mate it might help.

[gripper]

my 300tdi r reg 1998 has a white plug with 3 wires in it that plugs into the fuse box top right ish next to the flasher relay with white wire, yellow wire and a white/red wire.

the white/red goes to the starter via the imobiliser circuit i know this as i have taken a wire from her straight to the starter solonoid to bypass the imobiliser until i get a new remote programmed.

haven't tested the other wires except when i wanted a permanent live and it wasn't either of the other 2 so there must be another wire to feed the ignition attached elsewhere.

just looked in the haynes book but it only goes up to 1995, it says the red/white is same as i said to starter relay, white is power from ignition to everything else, and power to ignition switch should be brown.

makes no mention of the yellow wire in mine. best thing you can do is get a multi meter or test lamp to find a live.

[gripper]

just had a look at mine, the white plug is as i said just to the left of the flasher relay at the top right of the fuse box, there is a single blue ish wire plug above it and a multiplug with lots of wires below it,

of the 3 wires in the plug the yellow wire is top right connection, white/red is top left connection and the white wire is bottom left connection, there is nothing in the bottom right connection.

all these are as you look at them with the fuse cover down.

if you cannot find the wires or they have been unplugged then at least you should be able to wire another in if you follow the connections above.

if you can't see where it would be in the fuse box let me know and i'll take a pic tomorrow and post it for you.

[gripper]

looking at your 2nd pic i would say the brown wire is the feed to the ignition switch and the green is just the feed to circuits with the key in the 1st position such as the radio, the white will be for the next position with all the dash lights etc on and the white/red is for the starter solonoid.

do you have any power to anything or is it all dead apart from non ignition dependent stuff like the clock and side lights etc?

you can see where the plug goes in your 1st pic, there is a single green wire plug top of fuse box and just below that is where the white plug with the 3 wires (white/red, white, yellow) plug in, the plug has been removed. the 30 amp green fuse at the right is above the plug socket so you can see where it is.

[Davecrx]

Thanks Gripper

I had a look and this is what i have

looks like thats where i need to put some power into to get everything to go live, thats if the alarm haven't decided to re-arm it's self.

[gripper]

that's the socket just under the letter A, top left terminal is white/red which activates the starter, i actually bypassed it and ran a cable straight to the solonoid of the starter so it by passed the spider imobiliser,do this before it goes into this terminal if you are bypassing it then run a switched live feed to the injector pump stop solonoid as this also gets bypassed if the immobiliser is kicked in, of course if the immobiliser isn't on then you will be ok just using this socket, top right is the yellow wire and the white is the bottom left, nothing in the bottom right. i think the white is the return from the switch when it's on to power everything but i'm not certain. probably best if you can get an ignition switch for it then just plug and play or fit some spades with wires and try that. remember that the brown wire you have is permenant live so use that if the yellow wire doesn't have power at it.

[chromofoam]

Wiring diagrams are in the back of the Haynes manual.

[Davecrx]

All sorted now.. big thanks to gripper.

Now its time to work out what to wire into it

[Niamh]

i actually bypassed it and ran a cable straight to the solonoid of the starter so it by passed the spider imobiliser,do this before it goes into this terminal if you are bypassing it then run a switched live feed to the injector pump stop solonoid as this also gets bypassed if the immobiliser is kicked in

What about the glow plugs, are they switched through the immobiliser or not?

We've got a slightly temperamental immobiliser here that occasionally needs to be enabled and disabled with the plipper in order to start.

Niamh

[gripper]

i don't know i haven't tested them although the glow light on the dash still works, i think the immobiliser only cuts power to the stop solenoid and possibly fuel pump if it is electric, plus the starter relay.

to by pass it i found a switched live and ran a cable from that to the stop solenoid and tapped off the white/red cable from the ignition straight to the starter solenoid, this bypasses both functions and the car starts and runs just from the key, i only did this as my remote plip has stopped transmitting and as soon as i can get my new one programmed it will be back to how it should be.

don't forget the immobiliser kicks in after a few minutes after the key is switched off anyway, mine varies in length of time so that may be whats happening to you.

[Niamh]

don't forget the immobiliser kicks in after a few minutes after the key is switched off anyway, mine varies in length of time so that may be whats happening to you.

Not in my experience, I've restarted 300TDi Discos days after they were switched off without having to use the plipper.

Niamh

[Davecrx]

Snip

Edited May 14, 2010 by BogMonster
Publishing a means to bypass immobiliser probably not suitable!

[Niamh]

OK, so that's the starter, but the question of whether the glow plugs are controlled through the immobiliser remains.

Niamh

[Davecrx]

well I might have a play about to find out if I can bypass it. thing is I don't need glow plugs for my V8 running on ms lol

[gripper]

i'm sure they don't run through it, as far as i know the immobiliser only cuts power to the starter solenoid, fuel stop solenoid, and possibly an electric fuel pump but i think that last one is only on v8's as tdi's have a mechanical lift pump.