[W126 Coupe] powee problem

[David Fatovic]

help! on my dads 500 SEL there was a problem last year
where the ignition control module went bad. changed
that with the one from my 500SEC. I also changed the
rotor and cap. well it came up again yesterday. the
car wouldnt start again. I went to my 500sec and took
the new one out to put in my dads car. even though the
car had spark at the cap, the car wouldnt start. I put
the new ignition control module in and the car started
right up. that lasted the night and the car wouldnt
start again. so what could be the problem? it keeps
frying the ignition control module? help!