The pruning is crucial. Grapes form only on the first two nodes of the new shoot coming out of the old wood, two bunches per shoot (though occasionally this isn't perfectly respected). So if you only have a small number of shoots coming out of the old wood, which have grown very long, as could well be the case by now as they can grow like wildfire, you will mostly have extended shoots which won't form any grapes. There could be a cuople of forming bunches back near the old wood, but it will be hard to spot them deeply in the foliage. What you need to do is to train the extended shoots into a good framework for next year. Though if it has never been properly trained it might take a couple of years to achieve that. The proper framework has the right amount of old wood, not too much, not too little. For example, my grape vine comes out of a plot at one end of a south-facing wall. The first year I trained a vertical upwards. The second year I trained 3 horizontals along wires along the wall. And the third year I extended those to the end of the wall. Everything else is cut off in winter. So I now have a shooting point about every 8 inches along about 10 feet of wall, in three rows, and each row is separated by about 2 feet to give plenty of room. Each shoot develops 2 bunches of grapes. Sometimes I get 2 shoots so sometimes there are 4. Then there is the summer pruning, each shoot is repeatedly shortened so it doesn't go much longer than the grapes, you don't want extended shoots unless you are training them for next year. All leaf no grapes not good for grapes. Later I will thin out the less promising bunches, probably by a good 50% or so, as far more bunches than the vine can properly ripen are now forming. And even later I will ensure the developing bunches are well exposed to teh sun to ripen them by quite harsh leaf pruning. My E-shape training is only one possible form, and is dicated because the vine is at the ned of the wall. And such a large vine would be a completely wrong approach for wine grapes. For wine I shold have had 5 vines in that space and pruned each much harder.