For diesel engine vehicles, the wind derived for the manual transmission is not sufficient to prevent the temperature of the transmission oil from rising. The heated oil can cause either of the followings: (1) the contact point of the reversing lights switch inside the transmission wears resulting from chemical change, and eventually electrical continuity is lost, in which case the reversing lights will fail, (2) a chemical compound of high electrical conductivity accumulates causing a short circuit, in which case the reversing lights, the gauges and the warning lights will fail.