Electrical Gremlins and Ghosts

[raftel]

I am still sorting my 5 speed 528iT. Recently, I noticed that the right rear side was sitting lower than the left. I used my scan tool to reset the ride height, then left the car to sit for a few days.

Got in it today, and the suspension light was on. Tried hooking up my scanner, but it would not establish a link with the car. Weird. Ride height looked ok, so I proceeded to drive the car.

Then I noticed that although the HVAC fan came on, and I could direct airflow, the AC was not working. The light came on, but no cool air. Hmmm.

Then I noticed that the left side steering wheel buttons that control the radio would not work. The radio works, and the cruise control works, but the left hand buttons are not responsive. Their lights work.

The I noticed that the indicator lights for the blinkers and high beams on the instrument panel don't work. Note, the blinker lights and high beams work, but I get no indication on the dash, no "click" noise.

Battery is at 12.3 volts. 13.8 volt at idle. Loaded, goes down to 13.7.

Looked at the light control module, looked dry and ok. Carpets very dry under vinyl floor mats, but we've gotten a lot of rain. No sign of leaks in the car. And I still can't get my scan tool to communicate.

I feel that all of these things are probably electrically related, and I've reached out to StephenVA and Snotty, but we haven't figured this out yet - help!

[Chedley]

Yes, electric connectivity problem somewhere.
Check for water/wetness near the DME box, under the hood front driver side of the car. And get the scanner to talk to the car, first.

[balidawg]

Yes, I agree they’re all related.

Have you checked the electrical junction box in the front right under the carpet for water intrusion?
This thread by cn90 shows how to access it.
https://www.bimmerfest.com/forums/sh...d.php?t=459397

[raftel]

Thank you for the responses. I looked at the light control module and tried to lift up the carpeting as much as I could to see the box under the passenger seat. All looked bone dry, in fact it looked like it had never been damp. I'll poke around under the hood tomorrow to see if any moisture got to the DME.

In regard to getting the scanner linked in, any suggestions on next steps to try there?

[balidawg]

Most likely one or more control modules is interfering with communications on CAN or Diag bus. Usually you systematically unplug various modules on the affected bus until it starts working again, and that narrows down the offender. Look at this E39 bus diagram for reference.
https://www.google.com/imgres?imgurl...source=sh/x/im

[JimLev]

When you tried to connect your scanner did you have the engine running?
Also you may want to let the car go to sleep (16 min) then disconnect the battery for 10-15 min.
This sometimes fixes weird problems.

[raftel]

So I think I figured it out. In looking at the maintenance and repair history of the car (I have every receipt from POs back to purchase - 2" thick stack), I see that the original radio amplifier had failed due to getting wet, and a Pioneer head unit had been put in. I opened the rear left storage compartment, and found about 0.5" of water standing in it. The CD changer wire was submerged.

I dried it out, and rerouted the harness to keep it up. I'll have to figure out how that water is getting in there. But once I did that, all functionality was restored.

[JimLev]

The rear tail lights have a foam part that is suppose to seal the lights to the body.
That is probably how the water got in.

[StephenVA]

+1^

It's a wagon so check that Qtr window too with a hose....

[BimmrMeUpSnotty]

His floors are all dry, just that area at the amp. Yep Robert, like I mentioned a few days ago, check the tail light pocket. The foam seal fails on them every now and then. The other failure point, the foam seal on the bulb bracket too.

[BimmrMeUpSnotty]

The quarter window leak Stephen is talking about, water drips in in hard rain, runs on the bowden cable Coming from the latch to the inner door handle. On my old green wagon, this was happening, water was running in through the vapor barrier down the cable, dripping into the rear floor.I sealed it up with dumdum, butyl rubber to you guys who don’t call it dumdum. I basically formed a ring around the cable With a short dingleberry running down, like a half an inch that re-routed whatever may come dripping down the cable, and drip into the door shell outside of the vapor barrier, inside of the door shell. Then I formed another ring around the cable housing, and pressing it into the vapor barrier to seal it up as the cable comes through the foam. Never had that damn water come in again.

[edjack]

Dumdum was a name for a hollowpoint bullet.