I am an owner, but also work for a construction dealer (large equipment). We have had people with machines to be fixed and we hold until we get payment, alot of times. We will also hold a piece of equipment for a bad check/debt. In Alabama, they will put you in jail for a bad check. We once held a large dozer for over a year, waiting for payment. When he came to get it, we had to put new batteries and worked on it to get it started. Our own tractors on the lot gets started and run at least once a month. We had one small dozer that sat for 9 months for payment. After tearing into it and giving a price, owner did not want to pay to have it fixed. We already had $2500 in tearing it down. He was told up front that the dozer would not be worth fixing, due to the high costs of the parts. He first said go ahead and fix it. Later changed he mind. We sold it for the cost of the ticket.
If the amount of the bad check is close to the price of the equipment, it may be all the contractor gets for the bad check without going to court. Minus what may be owned to the bank. If you are running it right and taking care of it, you may be doing them a favor. It is sometimes better to run the equipment than to let it set.