Here is where the Turn signal switch / multi switch plug is and how to release it 1999 era Park Avenues

[cndknoll]

I will put this here in hope of helping someone : on a 1999 PARK AVENUE and possibly others of this era, the end plug is completely different than the Regal and such and located with a group of three plugs above the parking brake. the plastic frame work the three plugs are in pivots on two points, but I have never figured out , even when cutting the 4 wire ties, how it releases and pivots. There are 4 screws that hold that frame up. I did not attempt to remove it that way. The plug is the one closest to the brake pedal as you look up: you can get a long skinny flat blade screw driver in there and pry the metal clip and the plug will drop down and you can unplug it. Rather than try to feed the turn signal switch end back through the rectangle hole in the square frame ( if you are putting in a new switch) cut the darn plug off and be done with it and pull the switch and wires out . When replacing, instead of trying to feed the plug through all that mess and back down the small rectangle hole, route it and wire tie it along the steering column and reroute the plug end to the other plug and leave it out of the stupid frame work all together . Saves a LOT of head ache and time and frustration . And if you are replacing your turn signal flasher in the park avenue, before you try to cram the new one back in it's place above the other mess of other plugs, cut off the small parts that stick out with a razor saw : it will fit back in much better and allow it to turn much smoother ....the two part video on YOUTUBE is the best one for replacing the turn signal flasher on the 1999 era Buick Park Avenue cars. Have fun.......... you will not find a good video ( as of November 2024) about the end plug on the park avenue turn signal switch: there is a short clip on the tail end of one video , added as an after thought, it helped identify the plug and for that I was thankful, but does nothing to help you figure out how to get it out and unplugged. And the Haynes manual is useless. I ordered a Chilton manual used, I am curious to see how helpful it may be. And look for 1999 Buick Park Avenue C Platform Factory Shop Service Repair Manual Vol 2 , I just scored one on ebay for $23: I am hoping they can explain the factory way ( but I am not holding my breath)