Ho Locomotive coupler broke-how to fix

[rako]

Hi,I'm helping my 8yr old grandson repair his locomotives(commander set) and don't recall which type of coupler works best.Also,do you remove the entire housing on the loco or just fit a spring part back into it?

[ABC]

If it is broken beyond repair you can replace it with a Bachman E-Z mate medium shank coupler.

[rako]

thanks,I already picked up a few EZ couplers but now realize that the holder is either missing the top piece or damaged.If the four holes in the base remove the top assembly,is there a part I can replace or am I stuck?

[Jhanecker2]

There are books on repair & maintance of model railroad equipment . you may find it necessary to purchase one , this will become an ongoing problem . Also Checkout the Kadee website they manufacture the industry standard couplings and accessories. Most coupler repair does not require the disassembly of the shell to to effect coupler  replace-ment.

[rako]

 :)thanks for the reference.I figured out how to modify the broken holder(got a top piece of plastic and drilled a screw hole to retain the coupler.Works fine except the loco won't power up on the track.Worked fine before I put my hands on it.I'm an electronic engineer and know how to properly handle these kind of devices but don't  what happened.Are there sites that walk you thru troubleshooting?