Alternator replaced now explorer won't crank or start start

Hello, I’m Pete from the Car Genius team at RepairPal. I’m sorry you’re dealing with this concern on your Ford Explorer. On some models there is what is called a "fusible link" wire that sometimes leads from the starter to the battery or the alternator to the battery or to the underhood fuse panel that can short out when a repair like this is performed without the battery being disconnected. If you have already checked all visible fuses and found that they are all o.k. I recommend having the wiring inspected/checked to see if any fusible links are found that are burned out and need to be replaced. Usually you can tell if it is a fusible link wire by looking at it to see if it is burned or broken or if when tugged on it stretches and snaps. This inspection needs to be performed with your battery disconnected. It is also a good idea to check your underhood fuse panel to see if there are any large "Mega" fuses as these fuses are the new style fusible links that send power to all other fuses and if any of the Mega fuses are blown the affected fuse will need to be replaced. If you are unable to identify the cause yourself with a situation like this here it may be best to allow a repair facility to look into this concern to help identify the cause of the fault, a repair facility that specializes in electrical diagnosis and repair is usually best. If you’d like to find a trusted, certified repair shop in your area, you can check here: https://repairpal.com/certified. If you need more advice, or have any further questions about your vehicle, we’re here to help. Just give us a call at 877-913-1554 where we will be happy to assist!