Left tunr signal 99 Park Avenue

The turn signal relay is bad. The relay is located under the dash and is not easy to get to. I do not have a schematic and the only place you can find the info is from either a parts sotre, dealership or by purchasing a Haynes manual or Factory Type Service manual. The Haynes manual can be very generic as they are covering several models and years, but they are only $30. The Factory manuals are the best but costs hundreds of dollars. There is an on-line manual ccalled Mitchell! That you can access through this site. It is a great deal because you will have the equivelent of factory service amnuals for every car you own.
Also, be sure to disconnect the battery when working on electrical item as not to harm the Airbag system.
Let me know if I can be of further asistance.