what the heck auto/manual button do? '93 wrx wagon auto
 

had my car for ages (v1 wrx wagon auto jap import) and can't figure what the auto/manual button does other than illuminate manual light on dash. any ideas? also dif lock fuse holder under bonnet whats that all about?

sorted.
trawled through hundreds of threads and found this out.
if you select manual and use gears 1,2 or 3 the auto box will stay in that gear ie usually in 3rd the box will change down when you've slowed but while manual button is on will stay in 3rd same for 2 and 1. putting lever in drive seems to overide this and operate as per usual.
don't know why but never bothered to try and pull away in 3rd/or with the manual switch on if i want to change myself i just start in 1 and change like a manual, v.odd idea.