  We present multi-frequency simultaneous VLBI radio observations of the flat
spectrum radio quasar 1633+382 (4C~38.41) as part of the interferometric
monitoring of gamma-ray bright active galactic nuclei (iMOGABA) program
combined with additional observations in radio, optical, X-rays and
$\gamma-$rays carried out between the period 2012 March - 2015 August. The
monitoring of this source reveals a significant long-lived increase in its
activity since approximately two years in the radio bands, which correlates
with a similar increase on all other bands from sub-millimeter to
$\gamma-$rays. A significant correlation is also found between radio fluxes and
simultaneous spectral indices during this period. The study of the discrete
correlation function (DCF) indicates time lags smaller than the $\sim40$ days
uncertainties among both radio bands and also high-energy bands, and a time lag
of $\sim$70 days, with $\gamma-$rays leading radio. We interpret that the
high-energy and radio fluxes are arising from different emitting regions,
located at $1\pm12$ and $40\pm13$ pc from the central engine respectively.
