It sounds like you’re doing all the right things … Below a certain size, piles will not heat up. You’rs is slightly larger than the min (3x3 feet). Dead leaves compost slowly because they are high in carbon. Same with grass clippings. You say it’s moist; maybe it’s too moist: Does water drip/run out if you squeeze a handful? Maybe you have a paucity of microorganisms. These can come from the ground beneath it. If your pile is on pallets, it is not making contact with the ground. (Same for building a pile on plastic or cardboard, etc.) You can add ordinary dirt, but it will not produce a swift result. For that, you could purchase an inoculant of microorganisms. Adding fresh (hot) compost will contribute microorganisms, too.
It sounds like you’re doing all the right things … Below a certain size, piles will not heat up. You’rs is slightly larger than the min (3x3 feet). Dead leaves compost slowly because they are high in carbon. Same with grass clippings. You say it’s moist; maybe it’s too moist: Does water drip/run out if you squeeze a handful? Maybe you have a paucity of microorganisms. These can come from the ground beneath it. If your pile is on pallets, it is not making contact with the ground. (Same for building a pile on plastic or cardboard, etc.) You can add ordinary dirt, but it will not produce a swift result. For that, you could purchase an inoculant of microorganisms. Adding fresh (hot) compost will contribute microorganisms, too.
Hope this helps—