Diesel is pulling the cart around now! Glad, because it was so heavy for me to lug around during his ground training. With the open bridle and the blinker bridle, I have been pulling the cart with one hand while I long-lined him with the other so that he could get used to the noise following him.
Now that he's driving, it's HIS job to pull the cart. When I sit in it, my weight balances the cart so that it is much lighter. Yesterday we ventured out of the arena in the cart for the first time, and he was very well behaved. In the video above, we are practicing his slow trot and extended trot.