Changes to an existing depreciation schedule item

[CoonLFLLC]

i had to replace n expensive motor that died and was listed as part of an irrigation system.  The motor that died had to be junked so there was no salvage value. How do i remove the value of the motor from the piece of equipment and add the new value of the replacement motor? 

[AmeliesUncle]

My knowledge of irrigation systems is very limited, but my first thought is that it is not considered as a capitalized improvement.  That means you keep depreciating the irrigation system as you have been, and you DEDUCT the cost of the new motor as a "repair".