E51 Clearing the Head

Frogeyepete

Well-Known Member
Premium Member
E51 Owner
#1
There is a tremendous amount of useful information in this forum w.r.t. connecting up a new head.
I have purchased a Blaupunkt Kimberly 941 and am intending to try to install is in my E51 (emphasis on the word “try”). As far as I can see the Nissan adaptor takes care of all the speaker connections, a 12v constant, a 12v switched, power for the antenna (not sure how this gets through to the antenna via the new head unit), chassis ground, amplifier remote (no amplifier so assume this is not used) and a wire from dash illumination which I assume lights up the head unit at night time. In addition there are two loose wires coming from the plugs at the car end of the adaptor, black with a white stripe and orange with a black stripe. If anyone know what these are for please let me know, otherwise I will just tape them up.

The other end of the Nissan ISO adaptor looks like this:

The new head connector for the speakers is identical to that coming from the adaptor (whoohoo!).


The other new head connector that takes miscellaneous inputs from the adaptor, is not identical to the wires coming from the adaptor:
Head Adaptor
Yellow 12V +ve constant Red switched ignition
Black chassis ground Black chassis ground + extra cable to chassis
Orange dash illumination Orange dash illumination
Red switched ignition Yellow 12V +ve constant
Blue+Blue/White stripe Antenna power/Amp
The adaptor therefore has two extra inputs and the 12V constant and 12V switched may need changing over (depending on how the wires come from the car to the adaptor).
So far so good!

Finally – the rest:


These are other connectors provided by Blaupunkt for their head unit.
As far as I am concerned, the only relevant connection for the first connector is the brake connection, which I believe is a simple earth connection that should go via the parking brake to earth. I suppose this would cut out DVD’s on the head display while the car is moving, but not Sat Nav.
The second connector has the wiring for the steering wheel controls. It also has 3 AV phono input connections, but only the inner lead from each phono is wired into the connector!
The third connector has Video out phono connections, inner and outer. A number of speaker wire connections (all phono inner only) and a sub woofer phono inner and outer connection that could be useful at some time in the future.

The two outstanding questions in my mind are:

Why do I need to run audio connections to the rear of the car to plug in the head unit to the cars original system? I am not sure that my head unit has audio out for this anyway. If a DVD is playing surely the sound will go directly from the head unit to the speakers.
Are the original screens still controlled by a connection from the parking brake (among others), when the input is via the rear AV sockets.
I appreciate that these topics have been covered before, but I really can’t get my head (no pun intended) around the way the parking brake affects the screens. I understand that there is a fairly expensive adaptor that will fool the original system into thinking that the parking brake is on and the vehicle is not moving, but is this really necessary.
Any advice appreciate, otherwise I will suck it and see.
 

Attachments

Frogeyepete

Well-Known Member
Premium Member
E51 Owner
#3
I think this recent thread covers the screens and getting video to them http://forum.elgrandoc.uk/threads/satnav-output-to-main-screen.5269/
Thanks for the reference to that thread. I had seen it, but was was still not clear at the end of it exactly how the system works and if I need this Beat Sonic device or not. There seem to be two separate ways in which the parking brake can affect the video output of a head unit. One is the head unit itself which has a wire for a brake connection (I think, but would like it confirmed, that this is just a simple ground connection which could be made via an additional switch located in some convenient position). The other is the way in which it, along with other parameters, covered by the Beat Sonic device, affects the original Nissan Screens. I, like most people with these lovely vehicles, would like to be able play DVD's for the passengers in the rear while on the move. The passengers in question being my grandchildren, a most difficult audience to please.
 

MrRob_in

Part of the furniture (please de-cat your e51/2)
Premium Member
E51 Expert
E51 Owner
#4
Oe system has lots of interconnected modules that communicate with each other. For them to continue to work your headunit must mimic the oe headunit so Beat Sonic adapter does that. A handbrake override module may be within them or a separate unit but it’s more complicated than just a single signal wire because it alters how the nav element of oe system appears.
 

Frogeyepete

Well-Known Member
Premium Member
E51 Owner
#5
Oe system has lots of interconnected modules that communicate with each other. For them to continue to work your headunit must mimic the oe headunit so Beat Sonic adapter does that. A handbrake override module may be within them or a separate unit but it’s more complicated than just a single signal wire because it alters how the nav element of oe system appears.
I thought that taking an output video signal from the head unit to the rear AV sockets was enough to put a picture on the original screens. With this type of input does the handbrake etc still cut out the display on the original screens while the vehicle is moving?
 

MrRob_in

Part of the furniture (please de-cat your e51/2)
Premium Member
E51 Expert
E51 Owner
#6
Yes.
Unless harness adapter includes one. (Someone did find a hack to override it but I’m not sure if it works properly for all ... details somewhere on here)

Only front screen disabled (nav takes precedence).

Audo and Video follow separate paths and are switched from different models (or more than one) Audo includes phone and nav voice interface
 

Shaugi

Member
Premium Member
E51 Owner
#8
If the new headunit has a parking brake wire it should be easy enough to bypass.

The oe dvd unit links straight to the or sound system and the rear connections in the can are for external input...a new headunit is external input as it's not running through the oe dvd.

At least that's how I understand it to work.
 

Shaugi

Member
Premium Member
E51 Owner
#10
Baically yes.

My h/u has an extra earth wire from the nissan loom to make it work. That attaches to a screw near the unit. The parking brake wire definitely doesn't hook onto the same screw so I definitely can't have anything on screen while I drive ;)
 

Brendan1969

Here for life
Premium Member
E51 Owner
#11
My new UK head unit I had fitted by my supplier works on all 3 screens ( DVD ) and I have noticed there is a din lead plugged in to the drivers side rear socket adjacent to the middle seat row/rear set row and I did have mine over riden too.
 

Frogeyepete

Well-Known Member
Premium Member
E51 Owner
#12
Apologies @Shaugi for being a bit thick about this but - on one hand you say that the H/U can bypass the parking brake cut out by earthing the brake wire from the head unit (or at least I did and you agreed), but on the other hand you say that the parking brake wire (I assume from the H/U) doesn't hook onto the same screw as the earth wire. Confused I am. :confused:
 

Shaugi

Member
Premium Member
E51 Owner
#13
Apologies @Shaugi for being a bit thick about this but - on one hand you say that the H/U can bypass the parking brake cut out by earthing the brake wire from the head unit (or at least I did and you agreed), but on the other hand you say that the parking brake wire (I assume from the H/U) doesn't hook onto the same screw as the earth wire. Confused I am. :confused:
Well it's be illegal to bypass the handbrake and allow the screen to display while you drive. So it definitely doesn't attach to the earth wire on my h/u. Cos that'd be very naughty.
 

Robshann

Newbie
E51 Owner
#16
Well it's be illegal to bypass the handbrake and allow the screen to display while you drive. So it definitely doesn't attach to the earth wire on my h/u. Cos that'd be very naughty.
I've blown a couple of fuses trying to sort this problem out with my pumpkin hu. So although I'll not be watching dvd whilst driving, exactly what wires do I need to connect. I have a brake cable in the Pumpkin loom, do I connect this? If so, then to which wire/s does it go to?
Thanks in advance
 

Alan Morgan

Here for life
Premium Member
E51 Owner
#17
The Parking Brake Conundrum
> My E51 came with the 'hack' already fitted so I've no idea about the wiring for it
> However, I have the '£80' JPNZ manual which gives me some idea of how this might work and I share my thoughts with you on this:

> p210 of the manual shows the parking brake signal as being on pin 3 of the Navi Control Unit.
> This pin is one of 12 on a TH Type plug/socket (what ever one of those is?)
> The table on p212 gives the voltages on pin 3 as being 0v with the parking brake pressed down and +12v with the brake released

So far so good - but where do you go from here - the short answer is to proceed with caution! Why you may ask?
> Some earlier posts suggest doing various things with the HU connection. Personally I would ward against doing this because we don't know where the parking brake signal +12v is sourced from and we don't know what the HU connection actually does (or at least, I don't:confused:)
> To my mind there exists the possibility of causing damage to the OEM kit by 'squirting' +12v from the HU into the Navi Control unit or 'grounding' the Navi Control Unit's +12v in some undesirable way.

How I would proceed
> I would be on my knees peering closely at the parking brake switch to see how it operates. If it were a simple case of the brake operating a microswitch and simply putting the 'pin 3' connection to ground, then it would be quite a simple matter of disconnecting the 'pin 3' wire from the microswitch, and permanently grounding it, or by some other arrangement via a separate switch that reverts the parking brake inhibit function back to normal.

If you have not been able to follow the points I am making, it might be best to NOT proceed at all, but get professional advice.

Alternatively (and hopefully) another member comes along with the perfect hack in a well described 'How To' posting

@Frogeyepete - as you say up-post, wire it all in and see how the land lies - you never know, you may already have the 'Parking Brake' hack in place:eek:.

EDIT/UPDATE - please see my post #20 below for an updated view about this issue!
 
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Robshann

Newbie
E51 Owner
#18
The Parking Brake Conundrum
> My E51 came with the 'hack' already fitted so I've no idea about the wiring for it
> However, I have the '£80' JPNZ manual which gives me some idea of how this might work and I share my thoughts with you on this:

> p210 of the manual shows the parking brake signal as being on pin 3 of the Navi Control Unit.
> This pin is one of 12 on a TH Type plug/socket (what ever one of those is?)
> The table on p212 gives the voltages on pin 3 as being 0v with the parking brake pressed down and +12v with the brake released

So far so good - but where do you go from here - the short answer is to proceed with caution! Why you may ask?
> Some earlier posts suggest doing various things with the HU connection. Personally I would ward against doing this because we don't know where the parking brake signal +12v is sourced from and we don't know what the HU connection actually does (or at least, I don't:confused:)
> To my mind there exists the possibility of causing damage to the OEM kit by 'squirting' +12v from the HU into the Navi Control unit or 'grounding' the Navi Control Unit's +12v in some undesirable way.

How I would proceed
> I would be on my knees peering closely at the parking brake switch to see how it operates. If it were a simple case of the brake operating a microswitch and simply putting the 'pin 3' connection to ground, then it would be quite a simple matter of disconnecting the 'pin 3' wire from the microswitch, and permanently grounding it, or by some other arrangement via a separate switch that reverts the parking brake inhibit function back to normal.

If you have not been able to follow the points I am making, it might be best to NOT proceed at all, but get professional advice.

Alternatively (and hopefully) another member comes along with the perfect hack in a well described 'How To' posting

@Frogeyepete - as you say up-post, wire it all in and see how the land lies - you never know, you may already have the 'Parking Brake' hack in place:eek:.
Thank you very much for the info. It does get complicated doesn't it. What bugs me is that the unit i took out had some sort of bypass but I had to reconfigure the wiring and never gave the handbrake issue a second thought! It's like a bowl of spaghetti behind the head unit!! I'll give it one more go sometime taking your advice into account. Once again, thank you for your time and knowledge.
Rob
 

Frogeyepete

Well-Known Member
Premium Member
E51 Owner
#19
Don't think that anyone on this forum has identified a specific wire from the original Elgrand system that should be connected to the "brake" wire from a retrofit head unit. With the exception of the DVD player and Satnav, the original Elgrand ICE units are audio only, so no need for a parking brake connection.
So there are two totally separate systems.
1) New 2 Din all singing all dancing head, connected to Elgrand screens via cables to the RCA sockets behind driver seat.
2) The Elgrand screens and specifically the front screen.

I think the new head unit "brake" wire can simply be earthed by a switch connection to ground. (Possibly not exactly legal.)

If you want to use the Elgrand front screen while driving (satnav!). The screen's control system is not just looking to see if the parking brake is engaged, it is checking whether the car is in motion. This is where the various specialist wiring harnesses come in to override the signals that shut down the screen.

The above is just my understanding how things work. Very happy to hear that I've got it wrong. 😉
 

Alan Morgan

Here for life
Premium Member
E51 Owner
#20
@Frogeyepete
If you want to use the Elgrand front screen while driving (satnav!). The screen's control system is not just looking to see if the parking brake is engaged, it is checking whether the car is in motion. This is where the various specialist wiring harnesses come in to override the signals that shut down the screen.
You could well be right on that point in that going back to the diagram on p210, pin 6 is designated "Speed signal (2 pulse)", so you wonder what that is for. The speed pulse could be used for front camera control, any vehicle collision detection system or indeed the disabling of video to the front screen whilst moving? I really don't know!

When I did my initial strip down of the centre console, I found a blue box marked 'Bullcon Free TVing' - I never particularly though much of this at the time as I was full on with the camper conversion. However, a google search a moment ago reveals that this box of tricks is used to allow TV/DVD to be displayed on the front OEM screen whilst on the move, so as you say Pete, probably more than just a wire to/from the foot brake switch!
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