Strange, very strange

[Entwood]

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 ....   

[Kevin Wood]

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.