If both sides (right and left) don't blink on and off, the blinker "can" may be the culprit.
mine does not have one
I believe they are located on the starter.
Curb weight, 3,309 lbs
The original wheel size is 15"
The EGR (Exhaust Gas Recirculation) valve on a 1990 Buick Riviera is typically located on the engine's intake manifold. It is usually positioned near the back of the engine, close to the throttle body. To access it, you may need to remove some components for better visibility and reach. Always refer to a repair manual for specific details and diagrams for your vehicle model.
Regular ethylene glycol antifreeze............
It uses a distributorless coil pack and a crankshaft trigger sensor.
I just purchased a 1990 Buick Riviera with 45,000 on it for my daughter. However, I did have a brief period that you discribed with the car stalling out. I don't know if this will help, but I just read at another site, that it may have a faulty idle air control.
In the 1990 Buick Riviera, the horn is typically located behind the front grille, mounted on the front of the vehicle. You may need to remove the grille or access it from underneath the car to reach it. It's usually positioned near the front bumper area, making it accessible for repairs or replacements.
1990 lincoln town car
inside , right by the drivers right calf, it's hidden behind a pull out panel
Kind of bolts- they use both metric, and SAE so you will need a full toolset for both.