All of my car parchases have been through dealers so far. I currently have 3 cars and want to sell one maybe two. I’ve posted on marketplace and have received hundreds of messages with no serious people. I’ve listed all cars at great prices, but people see that and think they can get the car for even less than the discounted price it’s listed at. Dealer trade in rates are super low as well. Looking to sell to people that are shopping for cars and willing to pay under market value without lowballing beyond reason

First, I know next to nothing about cars so I'm definitely not going to explain this well. But I'm going to try because we're desperate for some help. My dad is the one doing the work on the vehicle and he's stumped. He replaced the long block after the issue that certain models of 2015 eco boost engines have with coolant leaks/intrusion. Now that everything is back together and there's a new battery installed we are having a problem repeatedly. BMS is reset. PCM is reset. We start the vehicle and it starts ok but the dash instruments are illuminated but don't seem to have power to them to give readings. If the car is then turned off and we try to re-start it, we DO see power to the gauges with readings but the engine cranks and doesn't ever turn over. This then repeats until the PCM is reset again and then the issue reoccurs in exactly the same order. Any ideas??