Omega Owners Forum

Omega Help Area => Omega Electrical and Audio Help => Topic started by: Entwood on 26 November 2012, 11:01:55

Title: Strange, very strange
Post by: Entwood on 26 November 2012, 11:01:55
Been down to the shops and an odd occurrence ....

Switched the engine off and once everything had stopped the battery warning light was flashing slowly, on for about a second, off for a second, on for a second, off... etc  :(

Restarted engine, pause, switch off .. all OK

Do shopping ... drive home, stop, exactly the same thing happens. This time I didn't "restart" the engine I just switched ignition back on, pause, off .. all seems OK and, for the moment, I can't get it to recur ....

Any thoughts from those who understand electrickery ???   got me stumped .. :(
Title: Re: Strange, very strange
Post by: kcl on 26 November 2012, 12:53:35
I've had this a few times after changing regulator to my alternator. It was "doomed" to be due regulator being a pattern one... Not had any problems though, only very intermittent illumination of battery light when turning off the car. Sometimes I've seen it blink, sometimes stays on for a few seconds.
Title: Re: Strange, very strange
Post by: Kevin Wood on 26 November 2012, 16:12:50
Voltage regulators are getting more intelligent these days. It strikes me that yours might be trying to tell you something, perhaps?

Was it a continuous flashing? Just wondering if it's trying to flash out a fault code?

I think I'd go through the charging diagnosis guide anyway, just to confirm that all is well.  :y
Title: Re: Strange, very strange
Post by: Entwood on 26 November 2012, 16:31:43
Voltage regulators are getting more intelligent these days. It strikes me that yours might be trying to tell you something, perhaps?

Was it a continuous flashing? Just wondering if it's trying to flash out a fault code?

I think I'd go through the charging diagnosis guide anyway, just to confirm that all is well.  :y

Good idea .. but it will wait until tomorrow .. it's dark .. and persisting it down ... :(

I'm assuming (always a risk) that the new alternator fitted in May :( would/should have had a new regulator on it ??
Title: Re: Strange, very strange
Post by: Kevin Wood on 26 November 2012, 17:55:24
Voltage regulators are getting more intelligent these days. It strikes me that yours might be trying to tell you something, perhaps?

Was it a continuous flashing? Just wondering if it's trying to flash out a fault code?

I think I'd go through the charging diagnosis guide anyway, just to confirm that all is well.  :y

Good idea .. but it will wait until tomorrow .. it's dark .. and persisting it down ... :(

I'm assuming (always a risk) that the new alternator fitted in May :( would/should have had a new regulator on it ??

Depends.. Was it new or refurbed? Possible that they just changed the brushes if a refurb.
Title: Re: Strange, very strange
Post by: TheBoy on 26 November 2012, 18:00:21
I'd be suspicious of the alternator - I've seen them pulse the light as they die, though I think its a result of the failure, rather than anything clever...
Title: Re: Strange, very strange
Post by: Marks DTM Calib on 27 November 2012, 09:01:09
Voltage regulators are getting more intelligent these days. It strikes me that yours might be trying to tell you something, perhaps?

Was it a continuous flashing? Just wondering if it's trying to flash out a fault code?

I think I'd go through the charging diagnosis guide anyway, just to confirm that all is well.  :y

Good idea .. but it will wait until tomorrow .. it's dark .. and persisting it down ... :(

I'm assuming (always a risk) that the new alternator fitted in May :( would/should have had a new regulator on it ??

Known good make alternator or a very dodgy unknown one?
Title: Re: Strange, very strange
Post by: Entwood on 27 November 2012, 10:11:14
Voltage regulators are getting more intelligent these days. It strikes me that yours might be trying to tell you something, perhaps?

Was it a continuous flashing? Just wondering if it's trying to flash out a fault code?

I think I'd go through the charging diagnosis guide anyway, just to confirm that all is well.  :y

Good idea .. but it will wait until tomorrow .. it's dark .. and persisting it down ... :(

I'm assuming (always a risk) that the new alternator fitted in May :( would/should have had a new regulator on it ??

Known good make alternator or a very dodgy unknown one?

Invoice doesn't say .. this is the one that was replaced by "Green Flag" agents when it failed "oop narth" and they did it for no labour charge .. cheaper for them than transporting me 200 odd miles with the cost of fuel/drivers hours etc etc. So the actual alternator cost £147 (exc VAT) but that is all the detail I have ..  at the time of fitting it was all very silvery and new looking, but that doesn't mean it wasn't  a refurbed job .. :(
Title: Re: Strange, very strange
Post by: Lazydocker on 27 November 2012, 12:36:42
I'd say it was almost certainly a re-furbed, pattern part ::)
Title: Re: Strange, very strange
Post by: Marks DTM Calib on 27 November 2012, 15:27:30
Vx one is 100 for the 120A and 170 for the 140A on TC (plus Vodka And Tonic)

It would be interesting to see how Green Flag handle the 'warranty' claim
Title: Re: Strange, very strange
Post by: Andy H on 27 November 2012, 22:27:22
I fitted a pattern regulator to my alternator after the original failed a few months back.

The warning light often gives a brief light show after stopping the engine. Can't decide whether I should be concerned or not :-\

Maybe I should buy a genuine regulator and keep it with the spare crank sensor that lives in the boot ;D
Title: Re: Strange, very strange
Post by: Kevin Wood on 28 November 2012, 16:45:12
It's normal for the light to show for a second or two after stopping the engine. The ignition feed to the light is cut instantly, but the alternator is still spinning at that point, so it supplies power to the bulb until it stops rotating.

What is unusual is for it to flash after the engine has stopped.
Title: Re: Strange, very strange
Post by: Entwood on 28 November 2012, 17:17:57
It's normal for the light to show for a second or two after stopping the engine. The ignition feed to the light is cut instantly, but the alternator is still spinning at that point, so it supplies power to the bulb until it stops rotating.

What is unusual is for it to flash after the engine has stopped.

Yup .. my thoughts too, but it's not done it again since ..

Battery after overnight stand - 12.6 v
Battery with headlights on after 1 minute - 12.4 v
Battery whilst cranking - 11+ ish -difficult to get a reading as it fires so quickly !! and I'm using a digital meter ....

Voltage @ idle - 14.4 (no load)
Voltage @ 2000 rpm - 14.4 (no load)

Voltage @ idle - headlights/foglights/heated rear screen - 14.1
Voltage @ 2000 rpm  - headlights/foglights/heated rear screen - 14.4

All terminals feel "normal" given its bloody cold !!!  :)

Title: Re: Strange, very strange
Post by: Andy H on 28 November 2012, 20:37:02
It's normal for the light to show for a second or two after stopping the engine. The ignition feed to the light is cut instantly, but the alternator is still spinning at that point, so it supplies power to the bulb until it stops rotating.

What is unusual is for it to flash after the engine has stopped.
The alternator doesn't have a freewheel clutch built into the pulley. When the engine stops the alternator stops too.

Mine sometimes shows a random warning light after all movement has ceased (sometimes more than once) over a period of 4 or 5 seconds.

My thinking is that the effect is inherent in the design of the pattern regulator, maybe something to do with a capacitor keeping the control circuit live for longer than it should :-\
Title: Re: Strange, very strange
Post by: Kevin Wood on 28 November 2012, 23:34:36
It's normal for the light to show for a second or two after stopping the engine. The ignition feed to the light is cut instantly, but the alternator is still spinning at that point, so it supplies power to the bulb until it stops rotating.

What is unusual is for it to flash after the engine has stopped.
The alternator doesn't have a freewheel clutch built into the pulley. When the engine stops the alternator stops too.

Mine sometimes shows a random warning light after all movement has ceased (sometimes more than once) over a period of 4 or 5 seconds.

My thinking is that the effect is inherent in the design of the pattern regulator, maybe something to do with a capacitor keeping the control circuit live for longer than it should :-\

Yes, but the engine doesn't stop instantly. ;)

The regulators are intelligent these days, however, so they can drive the light after shutdown, probably until the electronics have sensed no rotation for a certain period of time. Some have the capability to show faults in this way, although I've never seen it on an Omega. Of course a refurbed alternator might have a different spec. regulator, so might behave differently.

Sounds like no problem with Entwood's charging performance. See if ti happens again, I guess. :-\

I wonder if it happened when the battery was low or when towing the bedsit? Might be an indication that the alternator had gone into current limiting or thermal shutdown or something? Unlikely in this weather, of course.
Title: Re: Strange, very strange
Post by: Entwood on 29 November 2012, 09:44:25
It's normal for the light to show for a second or two after stopping the engine. The ignition feed to the light is cut instantly, but the alternator is still spinning at that point, so it supplies power to the bulb until it stops rotating.

What is unusual is for it to flash after the engine has stopped.
The alternator doesn't have a freewheel clutch built into the pulley. When the engine stops the alternator stops too.

Mine sometimes shows a random warning light after all movement has ceased (sometimes more than once) over a period of 4 or 5 seconds.

My thinking is that the effect is inherent in the design of the pattern regulator, maybe something to do with a capacitor keeping the control circuit live for longer than it should :-\

Yes, but the engine doesn't stop instantly. ;)

The regulators are intelligent these days, however, so they can drive the light after shutdown, probably until the electronics have sensed no rotation for a certain period of time. Some have the capability to show faults in this way, although I've never seen it on an Omega. Of course a refurbed alternator might have a different spec. regulator, so might behave differently.

Sounds like no problem with Entwood's charging performance. See if ti happens again, I guess. :-\

I wonder if it happened when the battery was low or when towing the bedsit? Might be an indication that the alternator had gone into current limiting or thermal shutdown or something? Unlikely in this weather, of course.

Nope , had just done a fairly short run however, it's only about 3 miles to the shop when it first occurred, and then 3 miles back for the second (and last) occurrence. I suppose the battery "could" have been a tad lower than normal as the car had not been started for 5 days before hand, but it cranked as per normal and no other indications of a low battery... although the alternator might have been shoving a reasonable bit back in to get it right up to optimum ....   :-\ :-\ :-\
Title: Re: Strange, very strange
Post by: Kevin Wood on 29 November 2012, 10:53:15
Doesn't sound like an abnormal load, then. Was wondering if you had current draw to the caravan fridge, plus lights and all the winter paraphernalia turned on.

I think it's going to be a case of keeping an eye on it and seeing if it returns. :y