Sudden Stop Sends Pipes Into Truck Cab

The ELD would be connected behind the dashboard,more towards the middle.

 

Your truck may not have been pre wired from the factory for a ELD setup. Customer/owner probably went the cheap route to try to save a few bucks on the purchase price of the truck.
On our trucks we use the diagnostics port on the truck for just that-diagnostics! And usually that’s only done during a safety inspection,software updates,etc. If there’s mechanical/electrical issues that render the truck inoperable and require the truck to be towed then the wrecker driver may plug into it to assist in towing the truck.