I think this problem was solved and also documented really well with a procedure and photos at the website:
http://65.39.242.200/~aghl/Aurora/index.html
The problem is caused by a small amount of grease inside the turn signal lever slowly flowing over time between the electrical contacts inside the turn signal - intermittently shorts-out the headlights or parking light switches causing them to flicker on and off. Cheaper than buying a new Multifunction switch is to open the existing one and just wipe away the excess grease.
You will need to drain the oil from your 1998 Oldsmobile Aurora oil pan. Remove the oil pan retaining bolts. Remove the oil pan gasket and clean the surface. Put the new gasket on and reverse the process.
In a 1995 Oldsmobile Aurora, the transmission dipstick is located near the back of the engine, usually toward the driver's side. It is typically marked with a bright handle, often colored yellow or orange. To check the transmission fluid, make sure the engine is running and the vehicle is in park, then carefully pull out the dipstick, wipe it clean, reinsert it, and check the fluid level.
Must remove the throttle air intake hose from throttle body. Then disconnect the wiring and remove the sensor and spray with mass air flow sensor cleaner.
To replace the oil pan gasket on a 1996 Oldsmobile Aurora, start by draining the engine oil and removing the oil pan bolts. Detach the oil pan from the engine block, taking care not to damage the mating surfaces. Clean the surfaces thoroughly, then place the new gasket on the oil pan. Reattach the oil pan, tightening the bolts to the manufacturer's specifications, and refill the engine with oil.
To change the oil pan on a 1999 Oldsmobile Aurora, start by safely lifting the vehicle and removing the undercarriage shield if equipped. Drain the engine oil and remove the oil filter. Detach the oil pan by removing the bolts securing it to the engine block, carefully prying it off if it's stuck. Clean the mating surfaces, install a new gasket, and reverse the process to reattach the oil pan, ensuring all bolts are torqued to the manufacturer's specifications.
To check the transmission fluid on a 1997 Oldsmobile Aurora, first ensure the vehicle is on a level surface and the engine is warm. With the engine running and the transmission in park, locate the transmission dipstick, which is typically near the back of the engine. Pull out the dipstick, wipe it clean, reinsert it fully, then remove it again to check the fluid level, ensuring it falls within the marked indicators. If needed, add the appropriate type of transmission fluid through the dipstick tube using a funnel.
As far as I understand, metal flacks (shavings) fall into grease around the switch and complete the circut. You need to replace the switch or you could try to dis-asemble and clean(dont recomend).....
needs cleaning --buy a good CD player cleaner iinsert it in and let it go --may take a coulpe of times but just keep inserting it til it takes --then clean at the very least 1 time a month .
google "multifunction switch" -- basically, it's a buildup of grease in the housing of your turn signal stalk which activates the circuit and makes that clicking sound even when the signal is off. The fix-it solution is to open the housing and clean the grease off the contacts.
Clean corrosion off contacts with fine steel woll, sandpaper, etc.
EGR vavle is clogged go to "you tube" search "clean EGR "
You have to pull the steering wheel...which means you have to disable the air bag, which means you should take it in. However, check all your bulbs first to make sure none are burnt out. Double bulbs in the rear lights need BOTH be working. Also, your turn signal flasher is located under the dash just beside your brake pedal (under the felt cowl, not the hazard flasher by the e-brake). Replace it if need be first. You can pop the little plastic face plate off your steering column by pushing the tab in front of the signal/cruise/wiper stem and get access to clean the turn signal contacts with canned air or a tiny (interdental) brush. This may clear up your problem. It did mine and I really hope to save you grief.