hi ferroequinologist , on my layout the main line is long and at either end is a reverse loop , both are operated by 0ne reverse module

as long as the train & engine are out of the loop it will work ( my DCC is Hornby but make is no matter ) several loops

nigefan --- I believe the Bachmann A4 class (UK) is the old Trix/Lilliput model ?

it may be worth looking up Trix - I stand to be corrected   

I always thought that real trains went clickety click when the wheel's/trucks went over the rail joints 

check that the rail is inside the rail joiner , Bachmann do sate this on their instruction sheet .


although if it is a regular click that would suggest split gears

another forum  ... nscale.net

https://www.nscale.net/forums/forum.php?s=77acad911f3dca537b6c2aa898fae64d

you may be able to post photos from your own album , again you may need a number of posts

hope this helps

edit ... another all scale forum again you can easy post photos .

https://bigbluetrains.com/index.php

try living in UK - you have to purchase a Dcc decoder extra from the loco - yes even Bachman loco's

reset the decoder ? cv8 - 8
also do dual decoder only run on DC with DCC set to 3 (factory setup).

how about a drive in cinema - pay booth/dinner and working screen ?
the modeler could sort out the car park .

that is sad , best email Bachmann then they know and you are on their list for repairs/replacement , if model not available Bachmann should/may replace with similar priced model .  You could be in for a long wait , so you should remind them later ?

is the loco the same model & size as the Bachmann UK 00/9 gauge Baldwin 10-12-D  4-6-0 ?
I have 2 both 12 volt DC and are super smooth runners .
my controller is the basic Bachmann , as comes with their train sets .

back to the chug ... best tell the TV company to re name the Kids TV series Rumbleton 
you know the one , it is called Chuggington   

back in 1960's Tri-ang UK (HO/00) made one not sure of scale , but 1960's mould maker and portable layout's it could be under scale ,

https://www.youtube.com/watch?v=E4jQzvEdq_4

Hi guy's -- I'm from UK and our standard mains voltage is 240 AC  and using a 3 prong plug/socket
live - neutral and earth .   maybee the OP was from UK , or has a pre owned set ?
hope this is of help .

if the A units are DCC , you need to program one to run cab forward , and the other to run long hood forward .
check with your controller instructions . (the Bachmann EZ command is capable to set this).

you might get more sence from Alexa than Bachmann spare's   

DJM-Oregon , you are correct the magnet system is for the later EZ couples also works with other make of magnetic couplers .
The knuckle couplers in the set are the first step up from rapido's - the knuckle coupler will couple to EZ Mk1 & 2 . (but will not uncouple automatic)
(Mk 1 EZ was sprung with plastic wisker - Mk 2 EZ has a small spring on the moving parts of the knuckle )