Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Malabo on 23 October 2008, 19:59:01

Title: 2.5TD CDX - Flat batt & no charge from alternator
Post by: Malabo on 23 October 2008, 19:59:01
Hi, again.

Hoping this one has sorted itself.
Got car within last two weeks. It had a totally flat battery when I first went to look at this friends car he wanted shut of. It had been standing >12 months. He replaced battery before I took car. Did he give it a full charge before fitting it? It started OK, brought it home.
Wife has moved it on drive a couple of times and it's started OK, but this morning - nothing.

Having jump started it there was a low voltage on the battery 10.8v or so, what problems have I bought, I asked as running it should be greater than 12v with alternator working. Anyway, short blast down steet and checked again 13+ volts so alternator now appears to be working OK.

Can anyone explain this? Was what appeared to be a duff alternator been some crud on commutator or something and possibly a drain on battery?

Malcolm
Title: Re: 2.5TD CDX - Flat batt & no charge from alternator
Post by: Bandit127 on 23 October 2008, 20:21:39
Could be the brushes are a bit sticky after so long.

Only 10.8V from a battery usually means the chemistry has been knackered. A slow, low current drain can do this... like an alarm. If it now fails to hold any charge for 12-24 hours you need a new one  :(

Sounds like the battery needs a full charge and then the car needs using properly. Appreciate that it might need MOT and stuff, so a top up charge will be needed every week or so until you can get it on the road. Either that or pull the negative connector off until you need it.

Alternators do not seem to be a weak spot on the Omega, very rare to get a posting with a problem on one.

Good job really, I had one go on a 2.6 A6 and the cheapest (motor factor) price I got was £440  :o
Title: Re: 2.5TD CDX - Flat batt & no charge from alternator
Post by: Malabo on 23 October 2008, 20:32:08
So that's a possibility, sticky brushes. Good to hear that alternators are usually reliable.
I remember a Cavalier I had, alternator bearing went just before I wanted to sell. Got a new Vauxhall one, car sold OK. A few weeks later, chap who bought it came back for alternator receipt. He had replaced battery and other things before having new alternator checked - faulty so required receipt.
Should get MOT cert in morning as had a couple of minors this afternoon whch I have sorted now. As you say, car needs using properly, I'll see how she goes.
Thanks
Title: Re: 2.5TD CDX - Flat batt & no charge from alterna
Post by: Entwood on 23 October 2008, 20:38:03
If the replacement battery had been left standing for any length of time totally flat before you got it .. the battery is probably FUBARRED ... the plates will be sulphated and won't hold a charge properly. No amount of charging either on or f the car will fix it.

It is not worth messing with, replace the battery, with a new one....  less than the cost of a tank of fuel.

 :( :(
Title: Re: 2.5TD CDX - Flat batt & no charge from alternator
Post by: Bandit127 on 23 October 2008, 20:38:09
OK.

Good luck with the MOT - let us know how you get on.

MOT is a good workout so check the volts when you get back - should be up around 14.4 at about 2,000 rpm. If so, the alternator is fine.
Title: Re: 2.5TD CDX - Flat batt & no charge from alternator
Post by: Matchless on 23 October 2008, 20:57:33
If you dont get 14V ish with engine running then take the alternator off and have a look at this guide http://www.omegaowners.com/forum/YaBB.pl?num=1153772945

Its very likely to be corrosion on the regulator contact as pictured in Mark's guide.
Title: Re: 2.5TD CDX - Flat batt & no charge from alternator
Post by: unlucky alf on 23 October 2008, 21:18:08
might be an idea to check for ignition light glow[maybe slight] when keys are out of the ignition, [best checked in the dark], if as you say the battery is a new one then something is draining it, anyhow if there is a slight glow from the ign light when turned off itll be the diode pack in the alternator, also check all the connections to the battery as these can corrode inside the crimps & cause a resistance which in turn can result in sporadic & unreliable charging.
Title: Re: 2.5TD CDX - Flat batt & no charge from alterna
Post by: Malabo on 24 October 2008, 10:25:43
Couldn't see any ignition lights on however dim. Voltage is 13.8v when testing across battery this morning. I'll see how she goes.

MOT PASSED
MOT - 3 issues. Horn - good bash got it going. Rear wheel rims got flats - swapped with spare. H/brake return springs - got some from JCT600 late yesterday afternoon. So took her back this morning and got pass certificate. Just £4.07 for new springs. Got to find a new wheel though