Classic/Antique Car Repair/Packard electrical
I have a 50 and two 51 Packards, both 50 and 51 wiring diagrams show the battery with a positive ground but the actual hook up of the 51s is a negative ground, they do start and runs well with all lights working but the radios do not work. How should the 51s be connected and if connected incorrectly what is the impact?
Someone has converted your car to negative ground, probably to attach some negative ground accessory so you need to check to see if that accessory is still there and needed. The car should be converted back to negative ground as it will run better. Auto Restorer magazine, autorestorermagazine.com, had an article recently featuring both the theory and procedure to return positive ground vehicles to original. Coincidentally, the example vehicle was a '48 Packard!
Good luck! You should be able to play that radio soon!