Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: ajsphead on 28 June 2016, 07:28:57

Title: Alternator service life
Post by: ajsphead on 28 June 2016, 07:28:57
Alternator no longer giving out any charge. I suspect the regulator pack but am happy to replace the whole thing. Is 127K attached to a nice low revving diesel engine near enough to the end of it's service life to justify total replacement ?
Title: Re: Alternator service life
Post by: Marks DTM Calib on 28 June 2016, 07:50:28
No not at all, the only parts that ever need replacing are the reg and occasionally the bearings.
Title: Re: Alternator service life
Post by: ajsphead on 28 June 2016, 08:23:24
Superb, thanks. I will save myself a fairly large sum of money.
Title: Re: Alternator service life
Post by: Diamond Black Geezer on 28 June 2016, 09:08:13
There's a rumour/suggestion going round that PFL alts are more reliable than FL - in this case is it still just these bearings/regulator affair that need replacing? Ta  :)
Title: Re: Alternator service life
Post by: Marks DTM Calib on 28 June 2016, 09:26:11
I have always found the pre 2002 alternators better than the later ones  :y

Same applies, the later ones have a different (and more expensive) reg which appears to fail more often.
Title: Re: Alternator service life
Post by: Diamond Black Geezer on 28 June 2016, 10:13:07
Ta very muchly  :)

Aiming to get a spare alternator, paint it, replace the bits that wear, so I've got an as-new spare to go on when the time comes. Did a test a while back and it's 'getting on', though still within tolerance, so to speak.
Title: Re: Alternator service life
Post by: Marks DTM Calib on 28 June 2016, 11:14:32
If its working then clean it and fit new bearings, job jobbed (and circa £10.....don't buy cheap no name bearings!)
Title: Re: Alternator service life
Post by: Diamond Black Geezer on 28 June 2016, 11:19:52
no point fitting a new regulator feller, then? Just bother with the bearings? One of those 'aint broke don't fix it' things?
Title: Re: Alternator service life
Post by: Bigron on 28 June 2016, 12:56:35
There is no predictable wear rate/MTBF figure for electronc parts, so no point in replacing the regulator "just in case" - a new one could just as easily fail sooner than your existing one, DBG - so no, don't fix it!

Ron.
Title: Re: Alternator service life
Post by: terry paget on 28 June 2016, 13:05:22
Do they have brushes? I am amazed they can turn out 120 amps. The current seems to be generated in the fixed stator coils, the rotor exciting them. Either the rotor is a permanent magnet, or it needs current to it. I wonder how they work?,
Title: Re: Alternator service life
Post by: Nick W on 28 June 2016, 13:21:58
There is no predictable wear rate/MTBF figure for electronc parts, so no point in replacing the regulator "just in case" - a new one could just as easily fail sooner than your existing one, DBG - so no, don't fix it!

Ron.


You could quite legitimately say that of the bearings. We only hear of the ones that have failed, but how many cars get scrapped with an original untouched alternator? Or any other rotating part for that matter. As these cars age we're going to see more parts that used to be considered bulletproof failing due to wear that would previously have been thought of as unusual.
Title: Re: Alternator service life
Post by: Diamond Black Geezer on 28 June 2016, 13:35:48
Indeed Nick.  :)

Me, now, I have replaced most of my doors, it's literally insane to spend time grinding out rust, welding new in filler, and a repsray, when a new door can be had for £25 or less, and swapped over in a lunchtime(ish) fast forward a few years and someone with a FC Victor would be faced with no other option than the very costly former.

I mentioned a while ago I'll be getting a spare ECU at some point. Met with several replies of 'why?' of course- well, no-one yet knows the true lifespan of these, the Omega being only really the second generation of cars to have such electronic systems. Once they go - poof! Car go bye bye. Unless spares can be amassed. 

Diff mounts anyone?....dun-dun-durrrr!!
Title: Re: Alternator service life
Post by: Marks DTM Calib on 28 June 2016, 14:18:32
Do they have brushes? I am amazed they can turn out 120 amps. The current seems to be generated in the fixed stator coils, the rotor exciting them. Either the rotor is a permanent magnet, or it needs current to it. I wonder how they work?,

Standard alternator setup, chuck a little bit of current (sub 10 amps) through the rotor field winding, lob in some mechanical rotational input and you induce a large alternating current in the stator windings. Rectify it and job jobbed.

Vary the field current to alter the output volts via the regulator.

There are a few tricks, the poles on the rotor are triangular which creates a non sinusoidal current in the stator (its quite square) which reduces ripple.

Thing is that there is no commutation of the field current (its slip rings and brushes) so no arcing and pretty much no wear as a result.
Title: Re: Alternator service life
Post by: Diamond Black Geezer on 28 June 2016, 14:36:44
I was with you all the way up to 'Standard'


 :y


https://youtu.be/7kgT5WPktIM?t=836
Title: Re: Alternator service life
Post by: Kevin Wood on 28 June 2016, 15:31:01
There are a few tricks, the poles on the rotor are triangular which creates a non sinusoidal current in the stator (its quite square) which reduces ripple.

Ahh.. Always wondered why they are that shape.
Title: Re: Alternator service life
Post by: Nick W on 28 June 2016, 15:43:26
Indeed Nick.  :)

Me, now, I have replaced most of my doors, it's literally insane to spend time grinding out rust, welding new in filler, and a repsray, when a new door can be had for £25 or less, and swapped over in a lunchtime(ish) fast forward a few years and someone with a FC Victor would be faced with no other option than the very costly former.



You're right about older cars, used doors are rarely any good even if you can find them.
I've done several doors, and consider them to be one of the easier repairs.


With the steel, filler and primer, this 1972 Avenger door was an afternoon's work and cost about £10:


(https://www.dropbox.com/s/jolvz9w3sq9cqkv/frame-patch-welded.jpg?dl=1)


(https://www.dropbox.com/s/6epbb6l9dqoqynq/skin-welded.jpg?dl=1)


(https://www.dropbox.com/s/potoqs0ljvtsm1t/filled1.jpg?dl=1)



Title: Re: Alternator service life
Post by: Marks DTM Calib on 28 June 2016, 15:43:41
There you go, one stator (taken last week by my good self)#

(http://i23.photobucket.com/albums/b394/Marks_DTM_Calib/Stator1_preVPI_zps7nywdayg.jpg)

And if anybody can spot the deliberate mistake......
Title: Re: Alternator service life
Post by: aaronjb on 28 June 2016, 16:35:36
And if anybody can spot the deliberate mistake......

Someone left the manual inside?
The wires are the wrong colour pink?
Title: Re: Alternator service life
Post by: tigers_gonads on 28 June 2016, 16:48:21
And if anybody can spot the deliberate mistake......

Someone left the manual inside?
The wires are the wrong colour pink?


 ;D ;D  That's the insulation  ::) ;D

Just make sure they keep the pikeys out of there
I believe copper prices are on the up  ;D
Title: Re: Alternator service life
Post by: dave-b on 28 June 2016, 18:49:23
And if anybody can spot the deliberate mistake......
Hard hat & hi-viz ??  ::)
Title: Re: Alternator service life
Post by: BazaJT on 28 June 2016, 19:45:38
That's amazing how they get summat that size under the Omega bonnet and still not have it looking out of place :D :D :D
Title: Re: Alternator service life
Post by: Kevin Wood on 28 June 2016, 22:58:19
Ought to keep the battery topped up OK through the winter. ;D
Title: Re: Alternator service life
Post by: jimbo125 on 29 June 2016, 08:16:23
So that's the stator motor then and I thought this thread was about the alternator :)
Title: Re: Alternator service life
Post by: Marks DTM Calib on 29 June 2016, 16:34:41
So that's the stator motor then and I thought this thread was about the alternator :)

So close, it is actually a motor stator and not an alternator stator......
Title: Re: Alternator service life
Post by: jimbo125 on 30 June 2016, 00:43:58
How do you get it under the bonnet, remove the SAI system?
Title: Re: Alternator service life
Post by: ajsphead on 01 July 2016, 20:16:41
Thanks for your help. Regulator replaced and all is now well. a visual check and a bit of measuring confirmed that the brushes had worn and were no longer in contact with the shaft. A small point to note, for those of us with Bosch alternators, there are 2 different regulators not determined by engine size or alternator output. To ensure you get the correct one you have to quote the Bosch code on the regulator.
Title: Re: Alternator service life
Post by: jimbo125 on 01 July 2016, 23:31:19
Thanks did not know that, had mine off during HG change and gave it a service in remarkably good nick for 18yo