What runs off the cigarette lighter fuse on a 1989 Riviera?
I don't know if this would help, but maybe. I just had the same problem on my 1996 Rivera. In my case, there are two main fuse boxes located under the back seat. On your model they may be located somewhere else. AT any rate, I replaced the 30 AMP fuse in one of the boxes and my cigarette lighter started working again. The funny thing is I went to ALLdata & subscribed for $25 per year, well worth it, to get the fuse layout & callouts. My situation was the pwr fuel cap actuator & the trunk release actuator, would not operate, so I couldn't put in gas or open the trunk, as this operated from the door handle console. Once I replaced this fuse, the situation was every thing worked including my cigarette light. Of all the callouts on the fuses, not one called out for "cigarette lighter" Gil Raker