I bet a previous owner thought they should all come on together and rewired them, which is why it keeps blowing fuses...
Yep, I think it's likely. It's quite a common misconception that a factory-fit bank of 4 lamps should come on together but the wiring isn't built for it. It's possible to do but you need to beef up all the wiring involved.
Mine we like it (all 4 together) when I bought mine and I had to undo all the hatchet job wiring to get them back to original function, the wires got really hot! I used the MPI wiring diagram that xrockengineer posted, though some of the wire colours were different)
What spots are fitted? That might give a clue as to whether your 4x lamps are factory fit or not. And as you don't have the additional fog lamp switch it could well be that someone has added the other 2 assuming it would be fine to wire them all into the driving lamp circuit.
Much more common to have 2x driving lamps factory fitted, only LE's like the Monte Carlo or Cooper 35th Anniversary (which mine is) had 4x lamps as standard though I think you could have a the additional 2 lamps as an option.
So i pulled the wiring out today and had a good look and it really does look like factory fit but there's been some meddling on the connectors, i only spent 30 mins investigating while my wife wasn't keeping tabs on me, will get further in to it some point this week...
