ABS System swap?

Hold on. You're only going to make it worse. The plugs being different is done because the modules are different and will not interchange. Even when the various wires are listed for the same functions, the solenoids they operate can have different resistance values, and therefore draw different amounts of current. That current flow is one of the things the module looks at to detect when a solenoid is partially shorted or has excessive resistance, and therefore can not do its job effectively.

The modules will also be different from a 1500 to a 2500 for example, and according to the weight distribution, such as between a dual rear wheel and a simple two-wheel-drive model. The two system can work identically, but one may have larger pistons in the calipers or wheel cylinders, and require different volumes or pressures of brake fluid to get you out of a skid.

The bigger concern is you never mentioned reading any diagnostic fault codes. There are hundreds of defects that will result in the system turning itself off, turning the warning light on, and most importantly, setting a diagnostic fault code to tell you where to start the diagnosis. You could have a defective wheel speed sensor, a blown fuse, or even something as simple as low brake fluid level in the reservoir, but you went for the least likely and most expensive solution.

If you did see a fault code, post that and I'll look up the definition for you. Those never ever say to replace a part or that ne is defective. They only indicate the circuit that needs further diagnosis. If a sensor or other part is referenced in a fault code, it could indeed be the cause of that code, but only about half of the time. First you want to do some electrical checks on wiring and connector terminals, and things like that.

Here's the connector views to help you put it back together. These are for a Sierra 1500 4wd. The second one is with rear disc brakes. Use the third one instead if you have rear drum brakes. If you have a different truck model, let me know and I'll find the right connector views for you.