  In this work, we investigate the phenomenological consequences of a doubly
charged scalar which may belong to different uncoloured scalar multiplets. This
doubly charged scalar couples to the charged leptons as well as gauge bosons,
which we parametrize in a model independent way. Restricting ourselves in the
regime of conserved charged-parity (CP), we assume only a few non-zero Yukawa
couplings ($y_{\mu \ell}$, where $\ell=e,\mu,\tau$) between the doubly charged
scalar and the charged leptons. Our choices allow the doubly charged scalar to
impinge low-energy processes like anomalous magnetic moment of muon and a few
possible charged lepton flavour violating (CLFV) processes. These same Yukawa
couplings are also instrumental in producing same-sign dilepton signatures at
the LHC. In this article we examine the impact of individual contributions from
the diagonal and off-diagonal Yukawa couplings in the light of muon $(g-2)$
excess. Subsequently, we use the derived information to inquire the possible
CLFV processes and finally the collider signals from the decay of a doubly
charged scalar. Our simplified analyses, depending on the mass of doubly
charged scalar, provide a good estimate for the magnitude of the concerned
Yukawa couplings. Our findings would appear resourceful to test the
phenomenological significance of a doubly charged scalar by using complementary
information from muon $(g-2)$, CLFV and the collider experiments.
