Problem setting up with inputs on 7i96s. Potential Electrical cabinet problem

Hey group, 
Thanks for the help so far. I rewired my setup so that it looks nice now, but I have stumbled upon an interesting problem. Here is the description:

I added an earth connection to the power supplies and inside my breaker box. I rewired everything, and it was time to wire the home switches. Previously, I had wired them on the power supplies, which were for the motors, but now I got an extra power supply for them specifically (24V). 
I wired them 24 from the power supply to the normally closed AZ7121 home switches and from there to the Mesa 7i96s inputs (the optically insulated ones with the LED). For some reason, they were very dim, and the home switches were not working during home all. I started checking connections, and it seemed to be an Electrical problem.
First i found out that if i distributed how i wired them and placed them on multiple power supplies they lit up better.
Next i saw that the Init LED on the mesa card (RED LED) was on
Next i realized that if i took all of the input wires except one (the wires that went to the inputs of the card for the limit switches) the one input LED became dim, But if i simply plugged in another wire from another home switch into another input (but disconnecting it from its power supply, simply leaving it hanging) the LED on the input lit up (dimly) as well. 
Next, I opened the breaker box for the CNC machine and saw that the Earth connection was touching the metal rail on which the breaker is connected. Now, there was no visible connection of a Line wire to the rail, but when I moved the Earth away from the rail and restarted the Mesa card, The RED INIT LED stopped. 
Now, potentially, the earth touching the rail on which the breaker was connected somehow was a problem. (Don't know why)
But right now I still have the same problem where the input LEDs are properly ON, only when I have 4 Home switches connected to 4 different power supplies.
Also, measuring from Line to the Earth shows 18V, if that means anything. 

It definitely seems that I have done something wrong, but Nothing seems out of order. If anyone has experienced something similar or has any ideas I am open to trying. 

Thanks

7i96/7I96S isolated inputs not working properly
usually means that the isolated input common
is not connected. (or connected to the wrong thing)

HAHA
Thank you!
I spent so much time on this, I had forgotten to hook that up. Still strange that the LEDs worked after connecting 4 switches. Anyhow. I can finish this now.