i have an 04 ml 350, it has blown the 15amp inst clust/heat/ac fuse. replaced it 3 times, kept blowing, put in a 20amp it made the check engine light come on, removed it right away and put in another 15amp, all was ok. drove it for an hour all was still good. wife drove it this morning, blew right away. any help would be great

 

2004ml350,

what i would do is start ML with no Heat / AC buttons on . and see if fuse blows. then turn heat on with no a/c engagement and see if fuse blows . you are doing an elimination try blower speed low to high , try a/c a think there is a seperate button for it

Jerry

 

tried that, it will blow a fuse even if the heat is off/ then it automasticly turns the blower on, and you cant turn it off unless you put in another fuse, which only last a few before it blows again

 

sounds like blower regulator is shorted i would unplug blower regulator
and retry
i believe its under passenger side dash , you get to it by removing plastic cover under pass. side dash

 

tried that still poped the fuse. stoped at napa picked up some more 15a fuses since it was getting cold, plugged everything back in and hasn't blown the fuse all day, ????? makes no sense