Check engine light & rpm problems

Check the main fuse that comes off the battery.

This may help, but check all the fuses

https://www.justanswer.com/buick/61gr1-buick-century-no-dash-lights-tail-lights.html

It is a known issue!

https://www.google.com/search?q=1991+Buick+ultra+no+dash+lights%2C+tail+lights%2C+or+turn+signals.

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run fault codes to find reason for the low engine rpm.. hard steering comes when the engine stops and there is nothing to turn the power steering pump.

You have a definite problem electrical. Get it checked quick because there may be a live wire cut and it could ignite or burn something out in the car.

COULD BE MASS AIRFLOW SENSOR...WENT BAD ON MY BUICK AND NEVER SET THE CK ENGINE..AND IT WAS DOING WHAT YOURS IS

ecu bad i had tht problem

Which engine do you have ?
Is the check engine light on when you turn the key on ?
Are you getting voltage to the coil ?

91 is OBDI not OBDII. The codes are just 12, 34, 45, and 48. 12 - diagnostic mode 34 - MAF/MAP sensor low voltage 45 - Oxygen sensor rich. 48 - not sure on that one What engine do you have? Are there any symptoms? Ill get you some more info once I know what engine.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

clean mass air flow sensor check for mil light

I would look for a fault in the ignition system such as a cracked spark plug. Might need a scope check to put your finger on the problem

For the Brake light to stay on and the fluid is up...sounds like your sensor is playing dead......

For the battery to die after only (4) hours..you have a very big drain on the battery itself.....without the vehicle right here to look at would be very hard to even guess...electrical problems are a hands on chore...

I'd take it to your garage/mechainc