[davedrivesody]

You need the factory electrical troubleshooting manual. With that, it's easy.

Locate the ground in the appropriate circuit diagram. Its photo number is listed beside it. Look up that photo number in the location photos at the back of the book. The ground is identified in the photo with an arrow pointing to it.

Dave

 

[davedrivesody]

@OD4, Sorry I didn't mean to leave you hanging. I didn't realize you were specifically looking for G503.

Just as Buffalo said, it's behind the glove box, far right side, just above the keyless receiver unit.

Dave