Ok well keep in mind that the '89 fog switch is rare and hard to find. Do not do this if uncomfortable.
The switch has a large plastic piece that moves up and down when pressed. Looks like a number 8 when viewed head on. Inside the holes of the 8, there reside the 2 bulbs, dash on top and the yellow indicator on the bottom.
The button has 2 "fingers" that move the plastic piece. These fingers are close to the bulbs, and have a tendency to soften and deform. When this happens, the switch doesn't work.
Now the switch will have to be removed and checked. It can be pryed from the dash using a screwdrier-careful not to scratch the dash.
The switch has three tabs on the back, pry them to take it apart. Carefully take note where the metal pice is that makes contact, also the spring-loaded ball. It fits the same way. Now remove the switch button from the rest of the switch.
The switch "fingers" can now be seen. They need to be straightened by using a soldering iron- do not touch the switch with the iron! Just hold it close enough to get it warm enough to bend with your hand. Once that is done, you can put it together and test. You should feel a click when it works.
Good luck. It's really easier than it sounds - just takes a while to describe.
