I recently replaced my power steering pump because it stopped working (the warning light came on) but it turned out not to be the problem, instead it was fuse no. 7 that cause the problem. That fuse is not the main fuse for the power steering. Now this fuse blows every time it install a new one but I don't know the reason. Does anybody have the answer for me?

First Welcome to the forum.

Fuse #7 is the ignition ON supply to the pump unit, it also feeds to the engine, but need to know what engine code/type you have to be able to help further

This is a Polo comfortline 2007 with a 1.399 cc engine and automatic transmission. (80 hp)

Ok the only engine code that seems to fit your description is the BKY and fuse #7 supplies the crankcase breather heater element & the oil level/temp sensor