<；P>；PROBLEM TO BE SOLVED: To allow obtaining of the initial stage of an abnormality in which an oxide film is formed between a terminal on the side of a controller 210 and a terminal on the side of a connector 296, and contact resistance starts increasing in a controller for loading onto a working vehicle 1. <；P>；SOLUTION: Control means 210, 213, 281, and 282 include alternative detection circuits 300 and 400 for alternatively detecting a change in the contact resistance rn in a contact part Jn of each of input and output system equipment with the control means 210, 213, 281, and 282. Furthermore, the control means 210, 213, 281, and 282 are composed so as to detect the initial abnormality in the contact resistance rn in the contact part Jn based on results of comparison of an output voltage V2 of the alternative detection circuits 300 and 400 with a specified voltage V0 pre-stored in the control means 210, 213, 281, and 282. <；P>；COPYRIGHT: (C)2011,JPO&INPIT
