Electrics stay on with key removed, all dash lights & rear brake lights on

[alz4m]

So here is my tale of woe- I will run through what I recall happening as some small detail may make all the difference and I'm hoping you guys and gals can assist.

1. I unlocked the car on the fob the other day and when I opened the drivers door the wipers did a sweep on the screen before I'd even got in.

2. Later the same day the air suspension collapsed- turned out to be a split bladder so I think this is unrelated.

3. I locked up the car on the remote and the alarm kept beeping so I locked it with the key and it was okay.

4.  I drove it (slowly!) home about a mile and noticed the gear selector light next to the shifter was flickering.

5.  At this point I didn't know the suspension was split so I checked the pump and all seemed okay so took the battery off to charge it and did so for a day whilst I was at work.

6. Reconnected the battery and nothing had changed with the suspension so drove it to my mechanic- other than the ride obviously being terrible the car performed as normal but the gear selector light was now completely out.

7. So my mechanic changed the split air bladder for a new one and the ride height returned to normal but now all the warning lights on the dash came on along with the rear brake lights when you remove the key- apparently the blowers and stuff also seem to work without the key in the ignition. He has also reported that the car starts intermittently but when it does start it drives fine and a test drive made the lights all go off but when he then tried it again all the lights came back on.

My guy is a proper bmw mechanic with all the appropriate diagnostic equipment and he's only been looking at it in between other jobs which were prebooked but he's a bit stumped as to why a simple mechanical fault has led to this apparent electrical gremlin.

In doing some research it seems that perhaps it's the alternator at fault? I did take a 60 mile round trip before the electrical faults started and the battery seems to be in good condition... Apologies for the long post but I thought one of the smaller details may shed some light on the problem.

Help and thanks!

[alz4m]

It's a 2001 4.4 v8 if that makes any odds.

Only thing I changed that could possibly make any odds is that when I checked the air suspension fuses I managed to lose both the one in the glovebox and the one in the rear by removing them by hand and then flicking them into some neverworld never to be seen again so I popped 10amp ones in their place. But I assume the car isn't so sensitive that this would cause any issues??

Oh and prior to this the PDC seemed to be intermittent but not showing any faults on the scanner which I was happy to forego.

[X5Sport]

Have you tried the simple 'battery reset'?  Remove the negative side for about 20 minutes and then reconnect it.  You could go further and disconnect both leads, wait a few minutes and then touch them together.  That will kill off any remaining charges in the car.

Check the battery leads are all connected and properly tightened.

Sometimes these cars can have an electrical 'brainstorm' and a reset can fix them.  It might not work, but it's the simplest thing to do - even if it does mean unpacking the boot!

Richard

[alz4m]

I assume he's tried a battery reset but I will give him a shout- it seems like such a random issue like I'm sure  the fix is a simple one (hopefully!!) especially as it was okay before.

I was only thinking an alternator fault as the car was fine on a relatively long journey and then electrical issues started coming even thought the battery showed a solid voltage- I know from my old e30 M3 that when the battery started dying it threw up all kinds of odd apparently unrelated faults and perhaps if the alternator 'gate' stays open when it's off then that may make the warning lights come on. Although I know very little about car electrics!!

I know he's checked the ignition switch already.

[X5Sport]

Next checks are going to be voltage related to make sure the battery is (a) good, (b) charged, (c) holding a charge correctly and (d) alternator/regulator is producing the correct voltage and current, and it's smooth.

Normally if an alternator goes bad you should see a warning light as the charge level on the battery and the output from the alternator roughly equal each other so nothing flows through that warning circuit.

But a bad regulator could cause issues with voltage spikes and those will definitely upset the electronics.  However the systems should not stay on with the key out.  Something very amiss there.

Something went bad whilst the suspension was being played with.  Without a wiring diagram of the ignition switch circuits and how they control power to the other modules I'm stumped.  It could be a short somewhere, or even a 'floating earth' where a wire to ground has not been connected/come adrift.

Richard

[alz4m]

Thanks for taking the time to reply. Hopefully I can get to the bottom of it and post a positive outcome- I've seen the problem reported across numerous forums but very rarely does someone post how it got resolved!

[alz4m]

It's been awhile and I still haven't got my x5 back (through mutual agreement with my trusted garage) but I spoke to my mechanic today and he suspects the body control module is staying live when the rest of the car switches off. In doing so the bcm is trying to communicate with the other modules and throwing up the odd faults- does that sound likely??

[alz4m]

Another update- seems that the fault may lie with the radio!!

[Steamyrotter]

Does the car not like your choice of music????

Only joking..

Trying to figure out how the radio module can do that amount of mischief!!

[alz4m]

Not too sure- I swapped the head unit to a widescreen one a few months back and it worked fine from the off but apparently in checking many many things on the car the stereo threw up some kind of odd reading when checking the wiring (which I didn't touch- it was plug n play) and with it disconnected the errors have gone away and it has been behaving as it should for 48 hours now so it seems to point to some problem with it.

What that problem is I have no idea but all being well I should have the X5 back this weekend ready to move house in a couple of weeks- which was the reason I bought it in the first place!! Fingers crossed.

[alz4m]

So it all seemed to be okay but when we put everything back together- the suspension pump and the related trim-the problem came back. The only thing I can think it is is the old traffic master unit as there seems to be some fairly rubbish wiring on it and putting it back into its home by the battery dislodged a wire that was previously okay.

To reiterate (pasted from another forum where I have asked about it)-

The car drives fine but when you turn the ignition off a number of the dashboard lights and rear lights stay on and the aircon also still blows and the car wont start for between 5 mins and 15 after it was last switched off.

It seemed to be fixed after removing the headunit (after checking the battery, ignition switch and various other electrical items) but when I put everything back together it happened again. but this time with the abs and traction control light stayed on whilst I drove it and the temp gauge kept sweeping back and forth with the external temp showing 46. Also one of the rear indicators stopped working but when I swapped the left and right bulbs and holders the same one still didn't work. Oddly I occasionally get music playing even without the headunit!

I think it's related to some dubious wiring on the old traffic master unit but when you disconnect and reconnect the battery it fires up straight away albeit with the temp gauge issue and sometimes with the TC light on. It seems to be something simple but it's been into the garage once already and they couldn't figure it out so does anyone have ideas? It seems that something on the car is staying live without the key and confusing the central system but could it just be the ignition switch even though it seems good?

Apologies for the long post and any help greatly appreciated!!

[max]

From your last post I can't make out if you have removed the traffic master system?
You mention old wiring, so I would try removing it out of the equation and see what happens. It could be as simple as its causing a battery drain.

[alz4m]

I haven't removed it yet, it looked quite involved!

[alz4m]

If it makes any odds the parking sensors were going off with the car in park,,, with the engine running and fiddling around with the tail lights they were beeping like crazy when I stood in front of them. Is there a fuse I can pull as they've never really worked since I had the car so maybe a broken wire or something is causing the problem...?

Probably clutching at straws...

[alz4m]

Curiouser and curiouser- reconnected the battery this morning and the car has run fine all day and turned off and on again with no problems at all.

The only problem I seem to have is that the rear left indicator still doesn't work but the bulb is okay (as itt works in the other side) and there's no warning on the dash. Other than that it's perfect.