In a pump-probe experiment, we measured dependence of yields and kinetic energies for symmetric N^2+ + N^2+ (2,2) and asymmetric N^3+ + N^+ (3,1) dissociation channels of N_2^4+ on time delay between few-cycle 800 nm pump and probe pulses. We observe that the asymmetric (3,1) channel is produced only for delays of up to 20 fs and completely suppressed for longer delays. The symmetric (2,2) channel is efficiently produced for all studied delays. We interpret that observation as an indication that the unpaired electron in dissociating N_2^3+ is completely localized on one of the ions after 20 fs.