Before replacing ANY electrical component, you should use a voltmeter to ensure that it has voltage supplied to it. Replacing parts without proper diagnosis is an expensive habit to develop. It is cheaper to take your car to someone and pay them for proper diagnosis than it is to just start throwing parts at it.

There is a fuseholder in the area of the master cylinder that has a large strip fuse inside. As mentioned earlier, check for voltage on both sides of that fuse. Don't look at it and declare it to be good. This fuse can develop a small crack along the end that will render it open, but look good. You can determine that a fuse is bad by looking at it, but you can't determine that it is good by looking at it. In other words if it's blown in two, then it's obviouis that it is blown, but it can look good but not be flowing current.

Good luck,