This is probably another crazy question. I'm gun shy now after trying my own methods that keep going bad. If I don't connect the grounds on the power cords, how do I ground these together. There is no ground spots that I can see unless I just connect the housings together. Are the metal housings a good place to ground to?
Yes, and that is why metal racks work so well, as if you scrape off a little paint the gear is really bonded. If you are going to bond gear you have to use thick copper braid. My racks are bonded with really heavy gauge copper braid.
In our former residence I did it this way.
When I moved the gear to our new location I made darn sure I used high quality racks.
Everything is bonded with heavy copper braid right back to the panel.
That keeps this lot quiet as a mouse.
When you are trouble shooting, it is best to remove, or as they say lift one ground at time, to see which ones are the culprits, or lift all the grounds, and couple them back one at a time to find the offenders. A logical carefully planned approach will always solve the problem. Just some sleuthing is required. All ground loop problems are solvable, and you don't have to throw money at it.