Alternator and AC woes

[Wonko]

Scratching my head trying to figure out why my AC failed and then a few miles later the alternator. This is on my 2006 V8.

The other day (hot day) I drove my car for about 60 miles, parked for about an hour then got back in to do the return trip. No AC. Blowing hot both sides. Sigh. I figure I'll get home and look at it there.

Not far from home all hell breaks loose. I get a message on the dash "EL Over current. Stop safely". Everything stops working. No power windows, no ABS, ESP, power brakes. Every single module starts giving an error message on the dash, it seems. Worse, there's a nasty burning plastic smell in the cabin.

I stop asap and have a look. Doesn't smell in the engine bay. Nothing to see. I limp home on small roads. Only one gear available to me - the trans is in limp. Had to hold the door open to get some air in the car.

At home, I disconnect the positive feed from the alternator, charge the battery and clear all the fault codes with Vida. All faulting modules seem to go back to working OK except the AC and the CCM. I get the message "Power system. Urgent service" or similar. Vida fault code says that the CCM can't communicate with the alternator. Car drives fine.

I'm resigned to the fact that I'm going to need a new alternator but I can't figure out why the AC isn't working. Or why that failed first then the alternator failed. The serpentine looks fine. No fault codes (other than air quality sensor which has always been there). The compressor is showing coherent duty cycles in Vida when AC switch is toggled and the pressure is around 1000 kPa which seems normal. The lines didn't seem to get cold though.

I hope that burning smell was coming from the alternator and not wiring inside the car...

I'm also hoping that the AC is not blowing cold because of the power system error message, but it doesn't seem likely.

Anyone have any ideas?

Thanks!

[SwissXC90]

Make sure you find the source, because next step could be this:

[Wonko]

Good. Then the problem would be solved.

[Tannaton]

I think the alternator is a common issue on the V8, more specifically the voltage regulator. I say that from memory of reading articles on here, it's also a tricky job to do unfortunately.

I would start there... as with most messages, get the codes read, which you have, and it points to the alternator.

If you search this forum another member, DaveSideways I think, posted some picks of what's involved to get at the alternator.

[Wonko]

Yes, I have also read that. And also Volvo have changed the design of the air duct to it, so it looks like a known weak point. Given where it is, I'm not surprised. Heat must be an aggravating factor. I'm not looking forward to changing it (I saw those posts about the extracting it).

Vida says it can't communicate with the alternator so it's either that or the LIN network somewhere inside the car. I won't know until I get a new alternator in.

Are there any good sources for OE parts? Volvo want about £600 for the part only.

[cheshired5]

Originally Posted by Wonko

Vida says it can't communicate with the alternator so it's either that or the LIN network somewhere inside the car. I won't know until I get a new alternator in.

Not necessarily.
If you have an AQS fault listed too, unplug the sensor as it may be disrupting the LINbus signals.

[Wonko]

True, it's just that that fault has always been present. I'll do it anyway.

Weirdest thing for me is why the AC stopped working just before the alternator hari-kari'd.

[Moose Test]

Sorry to hear that. Sometime I fret that I'm running on borrowed alternator time too, Final Destination Style, since I viewed but didn't buy the car that Doingitsideways went on to purchase.

"Worse, there's a nasty burning plastic smell in the cabin"

Yeah, that's not a bus fault. That's "high energies" causing the magic smoke to be released.

[Tannaton]

Originally Posted by Moose Test

Sorry to hear that. Sometime I fret that I'm running on borrowed alternator time too, Final Destination Style, since I viewed but didn't buy the car that Doingitsideways went on to purchase.

"Worse, there's a nasty burning plastic smell in the cabin"

Yeah, that's not a bus fault. That's "high energies" causing the magic smoke to be released.

Magic Smoke? Have you been in the pube with the holiday minkey again?

[Moose Test]

Originally Posted by Tannaton

Magic Smoke? Have you been in the pube with the holiday minkey again?

More like too much time down at the watering hole with Dave.

https://en.wikipedia.org/wiki/Magic_smoke