ABS assistance please....

I recieved a violation for the ABS light not functioning on my trailer. Today i took it into a TA (yeah i know) and had them check it out. Aparently the light is fine, but the ABS system was not getting power. After doing some digging, it turns out that my tractor ABS system is not working at all. All the relays are good, and fuses. There is no ABS power coming out of the pigtail connector to the trailer. When i cycle the key, there is no clicking of the ABS doing it's check. I know the ABS used to work, but not sure how long it's not been operating correctly. Is there any way to hunt down the issue... and test the ABS module???

It is a 2004 Western Star, as I stated, no ABS lights on in the dash at all, but it also does not come on when I cycle the key (should it?)
all the fuses for the ABS and relay are good (I swapped them around just to check)

Thanks for any help.

 

There is no power at the pigtail on the tractor side (line removed) so I'm guessing it must be farther back somewhere. It will have to wait till I get home next week to mess with it.... and hopefully it warms up some because i hate working on a truck in this cold weather UGH!!!!

And for reference, the tractor ABS does not cycle either. No clicks, no light on dash, nothing. When I turn the key to the "ON" position, the CE light and STOP engine light comes on but not the ABS lights... So I'm thinking the ABS module either has no power into it, or it's bad and sending no power out. I believe the module is located under the cab of the truck, under the drivers seat area??? I also know there's a control box for my dash in there somewhere I think.

 

Shouldn't be a problem fixing it, it's just the fact it's still winter back home and my shop is halfway torn down doing the pull-thru addition. So I guess it will be me laying in snow trying to figure it out lol