I would check and reset the accessory output voltage with a DVM to 12V.
If that checks out, I would disconnect the bus wires from the accessory terminals and hook up one simple accessory like a street lamp or light bulb to the CW-80's accessory terminals to verify that the CW-80 is working correctly. If it doesn't light up then the accessory output of the CW-80 may be defective. If it does work/light up then your problem is further down the line with the bus or how everything is hooked into it.
I'd also double check the voltage requirement for the switches to make sure 12V is not too much current. My recollection is that FasTrack switches like between 5V-10V.
Finally, it is not out of the question that the track side of the CW-80 would work correctly while the accessory side may be defective (don't ask how I know ). As best I can tell, the fuse is only on the track side, so the accessory side can be damaged w/o affecting the track side output. In addition, Lionel does not appear to sell a replacement circuit board or microprocessor to remedy the problem.
If the accessory side is damaged, you can still use the CW-80 to power the track and find a replacement transformer/power supply to run your accessories off of. Alternatively, you could upgrade to a better transformer or brick, like a PH-180, for track power and use the track side of the CW-80 to power your accessories and bring the power up slowly using the throttle.
Hope this helps.