D40 Stereo Install Gone Wrong. Please Help

[Dwayno44]

Hi all,

I recently purchased an aftermarket CD/DVD/SatNav etc unit off ebay to install in my 2007 Navara. After adapting the original stereo harness for use with the new stereo, I found that there was no Earth wire on the existing plug. I figured that I could get around this by hooking into an existing Earth nearby. I found a suitable Earth below the stereo, coming from the rear of the air-conditioning control. I tested the stereo, all was well, so i decided to screw everything back in place and put the centre dash panel back.

After doing so and turning the key on, an odd noise came from behind the air-con unit. Hard to explain what it sounded like. Intermittent for a few seconds. I turned the key off and tried starting the car. I heard the same noise again for a shorter duration this time, and noticed a range of warning lights on the dash (4WD, Battery, Filter?, Door (strangely indicating the opposite door to the one I had open), etc).

The car tried to turn over very briefly then stopped. I tried again several times, each time the car sounded less and less likely to start. Note, all over functions are working - lights, stereo (damn stereo) etc. Also note, that I had successfully started and moved the car only half an hour prior, and did not have any lights or similar on to drain the battery in this time.

I unscrewed the stereo and disconnected the connection, but the same outcome occurred. I.e. numerous warning lights and no start. I figured if the additional load had interfered with the Earth then disconnecting the load should return the system to normal?

I've hooked the battery up to charge for now to see if any difference results, but I'm not feeling confident at all. Have I activated a battery monitoring system or something? Or could I have damaged the wiring harness through heating it for heat shrink/cutting to use the air con Earth?

I'm sorry about the post not being too brief but I felt it was important to provide a lot of info. Thank you so much if you have read this far, and thank you in advance for any advise you are able to provide!!

 

[cafedex]

If you have removed the radio and put everything back to the way it was then all should be ok so something has changed. It sounds like you may have damaged some wires if using hot air on the heat shrink. Grab a torch and take a close look at the wiring loom to make sure there are no wires melted together causing a short. I believe the instrument panel is supplied signal via the can bus so you may have interfered with the 2 bus wires which is creating the problem you describe.

Dex

 

[Dwayno44]

Thank you so much for getting back to me Dex.

Unfortunately the plot has thickened since I posted.

I reconnected the battery terminals and tried starting the car with the same result.

I then attempted to jump start the car to eliminate a flat battery as a potential cause. At this stage the new stereo was still connected, hence the modified Earth connection behind the air con was still feeding to the stereo. Jump starting was a complete failure. More warning lights. No start. Then no lights at all. Nothing. Except an immobiliser light on the dash.

I disconnected the stereo completely and tried again, but by this point all I can get is the flashing immobiliser light. Ive tried locking and unlocking the car. I get blinker lights flashing on the dash when doing this, but the doors are not physically locking.

Car is currently on charge. Figured I'd leave it over night.

Am I right in thinking I've properly stuffed something here and may be in for a hefty Nissan repair bill? What a terrible afternoon

 

[BMGTZ]

try a completely different battery. Ive had similar issue that traced back to a dead cell in a near new battery

 

[Dwayno44]

Thanks!

I've tried jump starting from an idling car with a new battery, and I've tried connecting to another battery via jumper leads. If it was a battery issue, this would explain a number of the symptoms, but not the immobiliser or the whining noise behind the dash? Surely it's not necessary to reprogram an immobiliser each time the battery is disconnected and/or the car is jump started...

 

[Dwayno44]

Also, not sure how relevant it is but the original stereo had a security light, and I still don't understand how there was no earth wire on the original connection to the stereo......

 

[cafedex]

The earth on the original radio would be the radio chassis connected to car earth (negative) via the radio mount to car chassis.
Hope it's something minor. I hate it when such a simple job turns to a nightmare.
Try removing the battery completely for a while then turn on ignition and start to drain any remaining power. Reconnect the battery and try again. The ECU / electronics may have been corrupted somehow.
Keep us posted on the outcome.

Dex

 

[Dwayno44]

Hi Dex, thanks for clearing that up. Certainly makes a lot more sense now and explains why I couldn't find an earth. I'm trying to upload a picture of the other cable that runs alongside the aerial that has me stuffed as to what it is...

I woke up this morning and reconnected the battery. Still getting the flashing red key symbol. Makes me wonder if the original stereo was linked to the immobiliser somehow, ie flashing red light, although having said that I had moved the car after removing the original stereo without fault.

Also heard the same noise once after connecting the battery with the key on - I guess it sounds kind of like a motor/fan behind the centre section of the dash.

 

[Malicious]

A quick question how sure are you the wire you tapped into was an earth? These beats have lots of control lines to the BCM

 

[Dwayno44]

Yeah I "tested" by connecting the earth wire from the stereo. When I did this the stereo came to life and functioned correctly.

 

[Old.Tony]

I suspect a possible BCM fault, probably caused by current feeding in the wrong way.

The stereo and the instrument cluster share an earth point usually, and if you've found a new one, you may have caused power to flow in an unexpected way.

The BCM (Body Control Module) is responsible for door locks, windows, interior lighting, air conditioning controls and the central locking (and quite likely the NATS as well). Changing the BCM will require your keys to be re-registered with the car but thankfully there's a procedure for that.

First thing I'd do is take the earth point off the aircon controls and place it somewhere that's guaranteed to be chassis-connected. Forget any other point except the body itself.

Next thing is a full reset as described above.

If it still doesn't work, the BCM is likely to be faulty. Niss4x4.com.au could get you one from a wreck, or Nizzbits (pm him on this forum) would be able to get you a new one at reduced cost.

Of course, it's probably best to try borrowing someone's BCM first (after you've restored the electrics so that their BCM can't be compromised). If most things work with their BCM installed, it's time to get a new one.

 

[Dwayno44]

Wow, thanks for getting back to me.

Okay so if I'm reading this correctly:

1. Connect the stereo (new as I have the connection to power etc modified for the back of this unit)
2. Connect the earth to the chassis (so that it shares the same ground as the original stereo)
3. How do I then reset the bcm/nats system? I imagine anything I do now, I'm still going to get the flashing red key.

Long shot I know, but anyone in Perth able to assist and/or have a spare bcm lying around to test Tonys theory? Very long shot reading it back. Haha

 

[Malicious]

Yeah I "tested" by connecting the earth wire from the stereo. When I did this the stereo came to life and functioned correctly.

Oooh , Tonys advice is very good,
Unfortunately with new car a cable may present as a ground when in off state to prevent erroneous signals when the BCM is switched on these cables are low current signal paths, too much current and the smoke gets out of the electronics . All electronics run on smoke.
I hope you can solve it cheaply.

 

[Old.Tony]

The flashing red key in the dash just means that the NATS - Nissan Anti Theft System - is active. It's part of the BCM, and prevents the car from being started.

You have the steps pretty much right. The easiest way to do a full system reset is to remove the battery lead, stomp on the brake (count to 5 then release) then go reconnect the battery again.

 

[Dwayno44]

For real? I'll give that a go this afternoon after work.

Is this in anyway related to the fact that the original stereo had a security light but the new one doesn't?

 

[Dwayno44]

Also, should I be connecting the new stereo to the mounting screws (ie same earth as the old stereo), or run a wire back to the battery earth?

 

[Old.Tony]

The original stereo probably had its own security (with a PIN and everything) in it and may have "listened" to the BCM's security as well, that's something I'm not very clear on - my own original stereo, which I have, arrived in a box because it was ripped out before delivery and replaced with an aftermarket.

I wouldn't be too worried about it just yet.

 

[Old.Tony]

Also, should I be connecting the new stereo to the mounting screws (ie same earth as the old stereo), or run a wire back to the battery earth?

Just earth it to a point somewhere under the dash that connects to the body (like a mounting bolt for the dash). The chassis is supposed to be earthed - adding a secure connection to a guaranteed earth point is good insurance.

 

[Dwayno44]

Okay great. Have you tried the full system reset you describe?

I notice in the post at the top of this page you mentioned following the full system reset described above but did not describe the procedure

 

[Old.Tony]

I've done a full reset before, yes. Resets the system, tosses both trip meter values out, resets the fuel learning data in the ECU and dumps any error codes too. If you have a factory radio it will also require you to enter the PIN.

I was originally referring to this post (post 7 in this thread, I posted in post #11 which I guess is on a new page for you, my apologies, I should have just linked to post 7) but I summarised the reset procedure in this post.