Help! VZ has severe electrical issues

[full throttle]

Hello everyone. Hope you can help.
I have a '05 Berlina has approx 112,000km. 3.6lt V6 auto has some electrical issues creeping into things and wondering if anyone has expereinced same and how you fixed it.
1. Indicator lights randomly come on and stay on (not flashing) whether you are driving or not. As a consequence it has now melted two perfectly good tail lights.
2. The analogue part of the instrument cluster (fuel, temp, tach and speed) has ceased working. The digital parts and warning lights all still work fine. Checked fuses and what not. Nothing wrong there. Tried resetting the options in the menu but no change.
3. The a/c vents go to the screen on any acceleration up ANY sort of incline and come back to your set position as soon as you back off the throttle.

ANY useful help would be much appreciated.

Cheers.

[richardpalinkas]

looks like u may need to replace/repair the BCM. i know the indicators may be the bcm, and if they are all happening at the same time, it may be a faulty bcm

[richardpalinkas]

How to fix the sticky indicator in a VZ Commodore (BCM)

[bcw61]

Problems 1 & 2 might need some research me thinks.

Problem 3 is a bit easier to fault find, as I also had this very issue some time ago. The symptoms you describe are indicative of a vacuum leak in the control circuits of the HVAC, as a nil vacuum or loss of vacuum condition will cause the HVAC to go to the default position of demist with fresh air only. The fault can lie just about anywhere in the HVAC vacuum circuit, but my problem was caused by both leaking vacuum actuators & a vacuum leak within the HVAC mode selector switch. Split/leaking vacuum hoses, vacuum hoses that have become detached or are not connected properly, leaks in the HVAC vacuum tank & faulty vacuum one way check valves can also cause this problem. Repaired the problem myself, but still cost quite a bit to replace the faulty components. Not to mention that you need to be a bit of a contortionist (which I no longer am), to get into position to work on some of the HVAC components.

[bcw61]

How to fix the sticky indicator in a VZ Commodore (BCM)

For problem 1. I am not sure if a sticking relay is the issue for the OP in this case, as it seems that it is a random fault that occurs when driving as well. I'm pretty sure the sticking relay problem is only occurring when the vehicle is being locked, with the indicators coming on & staying on (possibly welded relay contacts).

For problem 2. Due to the number of analogue display systems that appear to have issues, I would start to suspect an instrument cluster failure (maybe a internal power supply problem???).

Apart from that & without having the actual vehicle to fault find, I can't really offer much else.

[richardpalinkas]

ah ok, just remember that thread, and he mentioned a stuck indicator so i thought it may be related. apart from that link i posted, i would not have a clue, may be a good idea to try and get a free/ cheap quote from an auto elec if someone doesnt have any other suggestions on here

[impulsive]

Sounds to me as if your cluster is on the wY out, perhaps a Holden technician will be able to diagnose. This is a new issue keep us posted.. My next stop would be Holden though, they have the proper diagnoses equipment.

[Trent L]

For Problem 3

For check the one way valve at the back of the engine near the firewall.

bcw61 is right but this link might help.

Calais climate control on 'AUTO' throws to demister when uphill grade ?? vacuum issue

[full throttle]

thanks to everyone who posted. I am looking into taking the car to an auto elec. Don't know who is good and who isn't so good.
It's a mine field out there.