I recently bought a set of the front and rear Athearn power trucks (#42010 and #42020) to convert a dummy unit to power. I did not keep track of which power truck is which when I took them out of the package. Is there a way to tell which is which besides the fact that the "clips" both have to face the same way. What would happen if the front truck was at the rear and vice-versa?
The clip is opposite the engineers side in this picture
http://www.athearn.com/Products/Default.aspx?ProdID=ATH42010
If you swapped front and back you would be delivering power from one rail to both inputs on your decoder or motor or circuit board.
Henry
COB Potomac & Northern
Shenandoah Valley
OK, so another way to say it is both clips should be "inside the two body frames" that are perpendicular to the main frame. See photo attached (left to right is front to rear)
https://www.flickr.com/photos/jrpfilestoshare1/29934218537/in/dateposted-public/
JRPboth clips should be "inside the two body frames" that are perpendicular to the main frame
It's not the way I would say it because if they were installed front in the rear and rear in the front they would still meet your criteria of clips inside the body frames.
Your photo is correct.
The 42010 is a front power truck according to Athearn: http://www.athearn.com/Products/Default.aspx?ProdID=ATH42010
I had success. Yes, you are correct...I had the trucks in the wrong place. Got power and all is good. Thanks for pointing this out to me. I just never looked closely and with some locos I did probably just had them in the right place to begin with.
JRP