  We study chargino pair production on the heavy Higgs resonances at a muon
collider in the MSSM. At $\sqrt{s} \approx 350$ GeV cross sections up to 2 pb
are reached depending on the supersymmetric scenario and the beam energy
spread. The resonances of the scalar and pseudoscalar Higgs bosons may be
separated for $\tan\beta <8$.
  Our aim is to determine the ratio of the chargino couplings to the heavy
scalar and pseudoscalar Higgs boson independently of the specific chargino
decay characteristics. The precision of the measurement depends on the energy
resolution of the muon collider and on the error in the measurement of the
cross sections of the non-Higgs channels including an irreducible standard
model background. With a high energy resolution the systematic error can be
reduced to the order of a few percent.
