John,
After loosing more hair than I have to loose, I came up with a real easy fix for the GS4 that stalls on switches and isolation rails. Now the GS4 will crawl though all the switches on my layout. Whew. Your note about the poor quality 3r/2r got me thinking about the common for a 3 rail setup.
Simply reverse one wheelset on the front truck of the tender, and reverse one wheelset on the trailing truck on the GS4 locomotive. That allows very good conductivity between all the drive wheels, with a resistance of about 2 ohms between any opposing wheelset. It's a backwoods way of bypassing the 3r/2r switch.
I marked the wheelsets that are reversed, and made a note to realign them to the stock orientation if it is ever to be used as a 2 rail.
Thank you so much for helping get this problem resolved. No track / switch rip-outs / rewiring needed as many suggested. The GS4 still gets a signal of 10/10 around the track with the quasi inverted pickup wheel setup. (~450ft of track - not a huge layout)
Now to figure out how to get the pilot wheels to trigger the Z1000 switches. Switches wont trigger until the primary drive wheels hit the isolation track. It doesn't look like they disassemble easily to do invert one of the pilot wheelset.
Whew.
