Please set the meter to measure AC voltage - it is the V with the tilde ~ over top of it. Hopefully, you are reporting voltage, as 14 amps would certainly make the transformer stop working and possibly melt something in the engine.
The problem that you have appears to be bad connections at the track joints of the flex section. Check that the pins are tight in the rails on both ends.
You should measure the center rail (red lead) to each of the outer rails (black lead) and compare the measurements.
You already know which end to check from the engine stall testing - the end with only 4 ( ?) volts or amps. Check without anything on the track and then with the engine on it again.
What are the results?
