Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: relluf on 09 May 2013, 09:23:33

Title: Battery light come on
Post by: relluf on 09 May 2013, 09:23:33
Hi , as thread title really
Did a 100 mile trip yesterday,all ok no issues at all, on the way home stopped for some fuel , when started off again light was on ,not flickering or dim or anything.
quick look around this morning all belts etc seem to be ok.
What should I be looking at?
I do have a multimeter but not really sure how to use it!!!
some advice needed please!
Title: Re: Battery light come on
Post by: henryd on 09 May 2013, 09:32:01
Sounds like your alternator has gone wrong,run the engine and check voltage at the battery,if all is working as it should be you should get 14.2-14.5v at the terminals  :y
Title: Re: Battery light come on
Post by: Dazzler on 09 May 2013, 09:34:03
Put the meter across the battery, read voltage.
Start car put meter across the battery, should be no more than 14v.
Rev the engine with meter still across battery, what is the voltage?

If voltage with engine running is only 12v or less then the alternator is faulty.
If voltage fluctuates alot with engine revs, faulty.
If voltage higher than 14v, faulty.

Try this and report back with findings.
Title: Re: Battery light come on
Post by: cem_devecioglu on 09 May 2013, 09:45:17
best method is to check the alternator voltage on load.. climate controls on, blower full, lights on .. now measure the voltage.. it must be no less than 13.5 volts and must not fluctuate.. 
 
imo your voltage regulator and some other parts must be serviced..
 
ps: also check the battery terminals and grounding connection ..
Title: Re: Battery light come on
Post by: relluf on 09 May 2013, 09:48:30
Thanks for your swift replies chaps .
Reading 12.6 across battery not running.
reading 12.3 with car running,
so does that mean its not charging?
Title: Re: Battery light come on
Post by: Entwood on 09 May 2013, 09:54:13
Thanks for your swift replies chaps .
Reading 12.6 across battery not running.
reading 12.3 with car running,
so does that mean its not charging?

yup ... it is using electricity to run, but none going back in ... hence the lower voltage when running .. should be up around 14.4 volts when running
Title: Re: Battery light come on
Post by: relluf on 09 May 2013, 10:00:28
Thanks
So source an alternator then or is it repairable?
Title: Re: Battery light come on
Post by: Andy B on 09 May 2013, 10:15:34
Thanks
So source an alternator then or is it repairable?

The choice is yours, either A N Other known to be OK alternator, or get yours repaired - you need a proper auto spark. Or replace the diode pack yourself, see Mark's write up http://www.omegaowners.com/forum/index.php?topic=90512.0  :y
Title: Re: Battery light come on
Post by: cem_devecioglu on 09 May 2013, 10:15:59
Thanks
So source an alternator then or is it repairable?

new alternators are not cheap , and I wouldnt do that job with an unknown second hand one..  servicing it, is generally the preferred method..
Title: Re: Battery light come on
Post by: relluf on 09 May 2013, 10:40:14
Once again ,thanks for all your input ,I love this forum where else could I get useful friendly info within an hour of asking !!

 cheers for all your input.

So silly question time.,....

IF battery is fully charged(should be) only driven a mile or so with light on, how far can I reasonably expect to get if I turn everything off? should get a couple of miles and back? or wait for swmbo to return this evening but really could do with it sorting today.
Title: Re: Battery light come on
Post by: relluf on 09 May 2013, 10:41:49
Thanks
So source an alternator then or is it repairable?

The choice is yours, either A N Other known to be OK alternator, or get yours repaired - you need a proper auto spark. Or replace the diode pack yourself, see Mark's write up http://www.omegaowners.com/forum/index.php?topic=90512.0  :y

Cheers Andy hadn't seen that.
Title: Re: Battery light come on
Post by: Andy B on 09 May 2013, 11:33:32
.....
should get a couple of miles and back?  .....

You should be OK for a short journey  :y
Title: Re: Battery light come on
Post by: Seth on 09 May 2013, 11:42:11
Earthing ... ?

Try clamping a jump lead from the battery NEGATIVE terminal to a manifold stud.
Then check the readings.
Title: Re: Battery light come on
Post by: relluf on 09 May 2013, 11:55:16
Earthing ... ?

Try clamping a jump lead from the battery NEGATIVE terminal to a manifold stud.
Then check the readings.

Thanks Seth
still the same readings
Will try and get it off and have a look at it ,but its north wales so that means its raining ,oh joy!!!
Title: Re: Battery light come on
Post by: Andy B on 09 May 2013, 11:55:31
Earthing ... ?

 ........

Waits for Mark to chip in with ........ ''it's zero volts!''  ::)  ::)  ::)  ::)
Title: Re: Battery light come on
Post by: Andy B on 09 May 2013, 11:56:06
....

..... so that means its raining ,oh joy!!!

Likewise here  :(
Title: Re: Battery light come on
Post by: Marks DTM Calib on 09 May 2013, 12:23:38
It is indeed ground or zero volts and not an 'earth'

If the vehicle will start then its not the strap from battery to engine thats an issue.

Usual cause would be a regulator failure, rectifier failure would generaly give a dim light due to reduced output where as solid light is more often than not no output.

Now alternators are pretty simple things and easily serviced by a compitent home mechanic, bearing replacement is the more challenging job and regulator replacement being dead easy to do.

Regulators are easy enough to get hold of for sub 20 pounds, to get the right one you will need the manufacturers part number (e.g. the Bosch part number)