The heated driver's seat on my 2004 Ford Explorer has worked in the past. More recently, the push button switch (located on the lower side of the seat) did not always turn on and now does not turn on at all(as would be indicated by a light on the instrument panel --and the seat does not heat up). I assume the problem is the switch --or of course, possibly a loose wire, but probably not the heating pad, since it always worked.

Is it easy to replace the switch?
Is it likely that a wire has been damaged or come loose?

Thank you.