when locos get 'lazy'

I always advocate using 'companion cars' connected to locos that run with fixed consists. The additional current collection makes these trains almost 100% reliable. The problem at times is that the bogies of the companion car are far better at collecting current than the rigid chassis of the locos themselves. After a period of operation, the locos become very reluctant to operate on their own. Careful cleaning is needed and after a little coaxing, they will begin to run again. I always let them travel a few circuits in both directions on their own before reattaching to the companion car.