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Ignition switch help required please

Pondrew

Pondrew

Lifer
Spaldingski
This is a Z3 (M54) so the connector plugs are different to an E85 but wiring is essentially the same (I think) so I am hoping someone may be able to help.....

My ignition switch has 2 auxilliary cables, in addition to the four 'power' cables....ie live in, acc, run and start.
I am trying to find out what they do. I have trawled through every wiring diagram I can find, looked online, and found nothing. There is no reference to these cables on any wiring diagram (that I can find).
I know that they are attached to an internal 'normally-closed' switch in the electrical connector, as they have continuity with the ignition OFF. However, they break contact as soon as the ignition is turned to any other position.

I have been wracking my brains trying to think of something that would be powered from the ignition switch when the switch is OFF, but breaks power when the igntion is ON. I can't think of anything.

HELP! It's driving me mad!

Picture of the cables on the rear of the ignition connector (they are the red/green and grey/green ones. They look like they are on a common connection in the photos, but they are not.
IMG_9799.JPGIMG_9800.JPG
 
bigwinn said:
Isn’t that something to do with the ews? I’ll have a look on the wiring diagrams
Click to expand...
Don't think so, as the only EWS wiring I can find is the antenna wiring attached to the outside of the lock cylinder. I am sure, though, that it is 'security' related, as I know someone who has just by-passed the switch and connected the two wires permanently with no ill-effects (apparently).

I can do the same but want to know what I am by-passing. Or I can run the wires through a N/C relay powered from the ignition switch to replicate it as it is now. :?
 
This is the 3.0 m54 e85 diagram

Inconclusive I’d say-

Red/blue comes from fuse 54
Red/green from fuse 58
Violet from the main panel connector x11011
Green from main panel connector x11012

If there is a black/blue one it’s s54/n52 engine only
 
bigwinn said:
This is the 3.0 m54 e85 diagram

Inconclusive I’d say-

Red/blue comes from fuse 54
Red/green from fuse 58
Violet from the main panel connector x11011
Green from main panel connector x11012

If there is a black/blue one it’s s54/n52 engine only
Click to expand...
I have all the wiring diagrams and can find nothing! Therefore it can't exist and must be my eyes playing tricks on me. :roll:

I am trying to think logically as to what would need to break power all the time when the car is 'ON', even with just the 'accessory' switched on? I can think of nothing except alarm related. And I know someone who has by-passed it and his alarm is fine (or at least doesn't nuisance trigger). :?
 
bigwinn said:
What about a signal to something like interior lights?
Click to expand...
Could be, but seems a bit extreme to put those through the ignition switch. Otherwise half the car would be wired to the ignition.

I am seriously considering putting a relay in the circuit, but it is something else to go wrong and may not make a sod of difference. :?
 
E86 said:
As bigwinn mentioned, could they be the connections for the "Toroidal coil EWS"?
Z3 EWS.png
Click to expand...
Thanks but it isn't that. I have those. Stupid car wiring diagrams pick and choose which bits of information they give.
Problem is that the exploded 'rectangle' shows everything within the ignition (except the two I need), but doesn't differentiate where they are. The EWS coil is miles away from the switch terminals! :roll:
 
Could it be for the gearbox lock on an auto?

Early Z4's came with wiring for the auto gearbox shifter even if they are manual.
 
Position 0 on ignition is refererred to as terminal 15. Terminal 15 allows power to certain parts of the car so you can use the radio etc....

So rather than thinking position 0 as an 'off' it's just another accessory power setting.
 
If you want to work out what exactly is powered by terminal 15 you really want to look at these 'always hot' fuses and I identify which ones are connected to the k-bus and they are then likely controlled by the EWS when the car is locked:

Screenshot_20240522_191612_Samsung Internet.jpg

One example I can think of is the key fob can operate the roof. This is very likely shut off when the key is turn to position 1 and beyond to stop accidental activation. So the GM5 is told by the EWS via k-bus that to only let the windows open with the roof but not by the internal window switch buttons. Like-wise the buttons inside the car for the roof will not be active until position 1 or 2 is selected on the ignition switch.

I'd say basically the guys above correct and that the EWS has over-riding control of position 0 (terminal 15)
 
E86 said:
Ah, how about this? The colours and switch behaviour seem to match your description.
Z3 S2.png
Click to expand...
That looks like it could be it! The wire colours match. So it is possibly just a radio setting which explains why it doesn't make any difference if always 'made' upon changing the wiring.
Thanks.
 
:thumbsup: That circuit is the the parking lights.

I have been wracking my brains trying to think of something that would be powered from the ignition switch when the switch is OFF, but breaks power when the ignition is ON. I can't think of anything.
Click to expand...

With the ignition off, the indicator stalk controls the parking lights.
 
E86 said:
:thumbsup: That circuit is the the parking lights.

I have been wracking my brains trying to think of something that would be powered from the ignition switch when the switch is OFF, but breaks power when the ignition is ON. I can't think of anything.
Click to expand...
With the ignition off, the indicator stalk controls the parking lights.
Click to expand...
Most excellent! Thank you so much. I wouldn't have thought of looking at the lighting circuits.
I now don't have to worry about putting relays in. I can just leave those wires connected together permanently and can now use my new ignition switch as per the old one.
Now to find an adjustable ten second delay timer to 'fake' the airbag warning light!!
I wonder what 'problems' the electricals will throw at me tomorrow?? :D
 
Turns out my expensive Bentley's manual doesn't have the above wiring diagram so I would never have found it.
The manual I have is for the US market only, so they obviously don't have the function for their market.

I posted the same question on a Z3-specific forum and got no help whatsoever. Good old Z4-forum always comes through (even for a Z3). :D

Thanks again guys! :thumbsup:
 
Pondrew said:
I can just leave those wires connected together permanently
Click to expand...

Shouldn't they be permanently disconnected? Otherwise the parking lights will be permanently powered, even when the ignition is on.
Disconnecting them would just disable the parking lights I think. As you say, you could fit a relay to keep the original behaviour.

Turns out my expensive Bentley's manual doesn't have the above wiring diagram so I would never have found it.
The manual I have is for the US market only, so they obviously don't have the function for their market.
Click to expand...

I found that wiring diagram here.
 
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