No fruit on grape vine

We moved to this property just over 12 months ago. We have two grape vines, one bears fruit ok but only on one half of the vine, the other had a few bunches of grapes but the fruit on the bunches were very small and remained green then finally shrivelled up. This year the second vine has no fruit on it what so ever.

Trim it, but not to the point vineyards do. grapes grow on SECOND year canes.

Feed it.
Water it well while the grapes are growing but stop before the ripening point, too much water then will cause them to split.

People think you can just ignore plants - they do far better with some nourishment.

Thanks for your comments. At our previous property and same with the other grape vine here that does bare fruit, I used to prune right back to the main trunk every year (like the vineyards do) and always ended up with a very prolific supply of grapes the following season. The non baring vine is the first I've struck that does this. I must say though it looks a different variety to the fruit baring one here and my vine at the previous property.

It may possibly be the rootstock that it was grafted onto? I've got a vine at my dads we tried to cut out as it was planted in the wrong place, every year it tries to regrow (rootstock as it was cut off low)

I'm just north of you & my 5 yr old grapevine hasn't produced many grapes until this season . I questioned my pruning methods, as I don't know heaps about it . but this year it's laden.
I'm wondering about pollination?
Now just to keep the bloody birds off them, when they ripen.

If you had fruit - real fruit, say pea size or more - and they shrivelled up, then possibly it's the deathly heat this year combined with a lack of water?
If the grapes were less than 2mm across when they shrivelled then maybe lack of pollination.

It could also be the pruning method used - depending on the type of vine. Most vines are fine with spur pruning, but some are not. and those that are unproductive with spur pruning will be really unproductive. You can tell if the vine has previously been spur pruned though, as it will have main arms that are thick and look to be a few years old.

You could try replacing the unproductive arm(s) at pruning time next winter. Take one of this years canes, preferably very close to the main stem - and bend and tie it down to become the main arm next year. Then, and only after successfully tying a new arm into place without breaking it, cut the old arm away. Helps if you choose the likely cane now and tie it on a diagonal angle so as its easier to bend down a bit further to close to horizontal at pruning time.

More food for thought: - The amount of sunlight your current growing canes get does affect the productivity of next springs new canes which will grow from that (what is then 1 year old) wood. This is one reason commercial growers "hedge" their vines, to let more light in. This helps ripen the grapes as well as lets light in to the canes that will grow fruiting wood next season. It also reduces mildew and other issues by improving airflow through the vine. Before hedging machines were invented they employed people to practise leaf pulling, where leaves are removed for the above reasons. A caution on this is to go easy and don't allow too much direct middle of the day/early afternoon sun directly on the grapes or they will get sunburned.

I also have a newish vine ,I started from a cutting 3 yrs ago. There was nil fruit until this year when I noticed the first bunch; only one , but it is a start.

What's prolific? Vineyards do it because they have 1000's of vines. Take a look next time you go past one.

There was a very sad looking vine when we moved here last year. It looks to be an oldish vine. I pruned it hard back and it has loads of bunches of grapes now. I have been watering every couple of days though. https://trademe.tmcdn.co.nz/photoserver/full/705630525.jpg