OT new alternator needed or low battery?

Lots of marginal batteries give up the ghost through doing infrequent and/or very short journeys at this time of year. Lockdowns really took it out of any marginal batteries.

I doubt if much ice would ever form under the bonnet.

Belt not tight enough might cause charging light on.

Was there a heavy frost?

Belt slipping due to heavy initial load. Usually, they squeak or screech. Might have been frosted.

Check for excess slack in the belt, or run the car more often than every four weeks.

Not exactly your local, then!

What sort of belt? Simple V, or toothed, or ribbed? I can imagine a simple V belt slipping under heavy load if it's a bit slack and gets water, ice or even oil on it. Old codgers have experience of simple V belts, but perhaps not so much of the others.

He's banned from all the closer ones.

Bill

The alternator should handle that load and still keep the voltage high enough to charge the battery.

Yes. I had to change a neighbour's battery for that reason.

That's ageism! If I knew who you were dissing I would tell him about you.

In the case of this old codger, steam is what forms under my bonnet.

But if you mean the car, I had this as a perpetual winter problem with a Viva. I think it was frozen condensate really. I tried tightening the belt. I also had it occasionally with the second of the two Sherpas I had.

Yes the light would brighten when the load was increased. Normally you get a shrieking noise though when a dry belt is slipping.

Bill

This is true. They also expect to see a starting handle and acetylene headlamps.

As a matter of fact I lived a dream of that era yesterday, in that I had a chauffeur.

Bill

A wee spray of wd40 is what is required .....

.. and every year the distance increases. ;-)

Not over a series of short trips like 5 miles or less. Cold cranking takes a good whack out of a battery and even if the charging system is perfect, that deficit really needs a longer run to be made good.

Naw. Copper grease. Copper grease stops that irritating squealing some fan belts make when they're slipping. ;-)

The sound of that screeching belt all the way to the pubs and back tells you it was ice on it!

I might be wrong, but I have never seen a toothed belt on an alternator, the logic used to be that at least the V belt would slip if the alternator seized. As Bill says the screech is pretty unmistakeable once you have heard it. I've never heard of ice on a belt, and it would not last long because of frictional heating.

Ice won't last long with a few hundred watts of frictional heating

A lot of modern belts that drive alternators, A/c compressors and water pumps are not toothed, but ribbed. To stop them falling off. But they are in essence simple flat belts. They have better friction thant v belts.

Toothy belts are for camshafts and distributors etc.

Was it squealing? Some cars use the same belt for the hydraulic pump for power steering and its amazing on cold mornings just how many cars seem to have slipping belts when they start up.

Brian

Might have been the old codger terrified at travelling faster then

Or Toby was kipping under the bonnet :-(

Yes, my bad. Toothed belts are for timing.