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[malcy_p]

Evening all! 

A short story - last weekend the Omega's battery decided to be flat. No worries, but on Tuesday night I needed the boot space so jumped her from another car and drove a 20 mile round trip in the dark to pick up some bookshelves. All good, didn't stop the car when loading, thought that would give the battery a little charge.

Friday morning, decide to take the car to work, flat battery. Boo.

Saturday afternoon, jumped the car and drove 10 miles to pick the lad up from a school Christmas concert. Pulling into the carpark the alternator light comes on, cue SWMBO running in to get the boy and off we go. All running fine until about 2 miles from home when the inevitable happens and the battery dies for good. SWMBO (being the more athletic of us...) runs the 2 miles home and picks up the 4x4 and drives back. Omega towed to the bottom of the drive by the garage. Jump started her again and measured the voltages - 13.6V with jump leads attached, 12.1V without. I diagnose the fault to be a dead alternator. Leave the car there and go indoors.

Today (Sunday) I go to tackle removing the alternator. Bonnet open, tools out, then I hear a buzzy-ticking noise from the brake servo area... Power sounder territory.

Off with the scuttle, and sure enough the power sounder is the source. Ign on, unplug, tape up, done.

Carried on removing the alternator, get it on the bench and remove the reg and brushes. Brushes look fine, haven't tested the reg as need a beefier variable PSU than the one I have at home.

Anyway, I have ordered a new regulator unit from flea-bay. Will fit that when it comes.

So, questions (for those who have read this far...)

A) Would the power sounder going faulty possibly kill the alternator some how?
B) Would the alternator going faulty possibly kill the Power sounder some how?
C) Am I looking at a co-incidence?

2003 Omega 2.6 MV6 auto....

/malc.

[RobG]

A) Nope, it`ll kill the battery.
B) Unlikely
C) Probably

[05omegav6]

But even a working alternator can only resuscitate a dying battery a finite number of times

Trying to charge a dead battery AND meet the demands of lights/heaters/engine might have pushed the alternator over the edge...

[malcy_p]

But even a working alternator can only resuscitate a dying battery a finite number of times

Trying to charge a dead battery AND meet the demands of lights/heaters/engine might have pushed the alternator over the edge...

Ah, so the PS dying might have killed the battery last weekend, and then again by Friday morning - then the alternator threw in the towel from having to re-change the PS-drained battery several times?

Kinda makes sense!

Thanks guys! 

[malcy_p]

For completeness, the new voltage reg/brush unit I ordered from eblag (£21.99, free delivery) arrived last Thursday and I fitted it this afternoon.

Long story short - problem solved, charging light out and a healthy 14.4v showing when the engine is running.

Lovely! 

[05omegav6]

 

[biggriffin]

I do hope the powersounder was removed and given a decent burial.

[malcy_p]

I do hope the powersounder was removed and given a decent burial.

Oh indeed - removed and put on the wood chopping pile behind the barn, along with a 2kg lump hammer. Had there been any life in it, and had it gone off it was away from the house and the neighbours, and I reckon one good smack with the hammer would have been the quickest way to silence it! 

In fact, it's been there a week so I can probably safely take it to the recycling centre with the other electrical stuff I have to take.

/m.

[Marks DTM Calib]

Extra drain on an alternator wont kill it, there designed to 'manage' over current situations.

And given the size of them and thier ability to output juice, if the power sounder load had been to much then it would have been the old 'fire, dah dah doo doo, fire....' (in a Prodigy esq tone)

[malcy_p]

Extra drain on an alternator wont kill it, there designed to 'manage' over current situations.

But given as it was the voltage regulator and brushes that I swapped, and that the brushes were ok, could the extra strain of twice times recharging a very flat battery killed the regulator? 

Pleased that Keith and the boys didn't get a look in though... love my Mig!   

/malc.

[Marks DTM Calib]

No as all the regulator does is control the relatively low field current (and the brushes never wear out on these as its a slip ring setup at low ish current).

IF it was current related it would be the rectifiers that would go (and they just never do on these).

In the case of high current delivery, the regulator delivers its max rated current (which it does pretty for most of its operating life in relaity) to the rotating field but as the unit is operating at its max VA the voltage output will limit.

Hence strain may increase on the rectifier diodes (but not by a great deal as when the voltage drops the current output drops and hence it self regulates).

Interesting as the later alternator as fitted to the 2.6 and 3.2 is not nearly as reliable as that on the 2.5 an 3.0

[malcy_p]

No as all the regulator does is control the relatively low field current (and the brushes never wear out on these as its a slip ring setup at low ish current).

IF it was current related it would be the rectifiers that would go (and they just never do on these)

Fair enough - I was just trying to make sense of the sudden onset battery flattening, the power sounder failure and then the alternator failure. All I know for sure is that changing the reg unit fixed the problem 

[dbug]

Sequence of events on our Estate was - power sounder failure and flattened battery.  Power sounder removed and binned, battery charged - all ok for a couple or days.  Then charging light on, battery flattened, alternator failure.  Recon alternator fitted, battery charged - all ok from then on.