I'm assuming that it has power steering - if so i'd check that first. All the connections, pump ect.

Also Isuzu Troopers have a terrible track record for dodgy electrics.

BUT - i'm going go for the aliment. You can adjust it yourself, all you need is a laser to aline it with the proper toe in.

I think that's what your problem is - I supose your just going to have to check it all - but it should be something you could do with a car jack.

Also check all the tyres - as you go round corners it takes more rubber off on the inside - that's something we have a problem with in England - all our roundabouts mean the inside side of the tyre wears out faster - so we change em over every now and again.