IF your service light switch is the same as my '89, it is BEHIND the general area of the speedometer. Take off the panel under the instrument panel, and feel around up under and around in the area by the speedometer back. Reach up around it and you should feel a small 'switch' that you can move up and down. It seems to me the switch is more toward the left, the drivers side, than the center, not sure. You should be able to find it. It has been many months since I did mine; can't remember which way to flick the switch. If it will click up,then do that and see if the light goes off, otherwise it is down. LOL. Don't "force" it.I am not sure if your '93s switch is positioned the same as mine, but I am sure it is NOT in front by your instrument panel. "They" do want you to be able to turn it off yourself so simply; "they" want you to come in for service! Maybe another BBer can be more explicit!