A vehicular lamp that illuminates a plurality of light source units
adequately. The vehicular lamp that is used for a vehicle includes a
plurality of light source units that is connected in parallel, an output
controlling switch operable to intermittently carry an electric current
by repeating on and off, an output coil operable to output electric power
according to the current flowing into the output controlling switch in
synchronization with the timing when the output switch switches, a
selection controlling unit operable to select at least one the light
source unit in synchronization with the timing when the output
controlling switch switches and cause the selected light source(s) to
receive the power output from the output coil, and a malfunction
detecting unit operable to detect malfunction of each of the plurality of
light source units, in which the selection controlling unit selects at
least one the light source unit among the light source units from which
malfunction is not detected when the malfunction detecting unit detects
malfunction of either of the light source units.