Actually, upon further inspection of the circuit, there seems to have been a major reversion in 1991. For the 1991 model year, the aux fan circuit contains NO FUSE. WTF MB?
The above fix works if you have anything other than a 91. If you have a 91, do the above and then cut the red wire going to the high speed relay, and insert a fuse holder inline. I guess 15 or 20A would be about right.
1990 and older. Fan circuit is protected by fuse.
1991. No fuse in circuit, add one.
