This may or may not help. It is a well-known problem that '86-'88 300E models have blower motors that build up resistance as they age and will blow fuses on a daily basis if not corrected. I don't know if your '82 may be exhibiting similar problems or not, but MB has a "fix" being an inline fuse bypassing the fusebox. I don't know the part # off hand, but hopefully someone reading this thread does...or contact your dealer.
1996 SL320 97K miles
1996 C220 130k miles
1992 500SEL 170k miles <---sold
1986 300E 216k miles <---sold