To check the Power Steering fluid on your 1991 Caprice remove the cap on the power steering pump fluid reservoir and check the level on the fluid level indicator. If the fluid is warm(about 170 degrees)the fluid level should be at the "Full Hot" mark. If the fluid is cool(about 70 degrees) the fluid level should be at the "Full Cold" mark.Always use the correct power steering fluid to avoid damage to the hoses and seals which will result in fluid leaks.
It should be noted that the reservoir (pardon my spelling) is located under the alternator (On my '91 with the 305, that is) - So you can't do it while the car is running.....Kenny
Check the front end components for the cause
At the power steering reservoir, the same place you check the level.
Check the brake light switch on the brake pedal. Might have to replace it.
If there is no light at all in whole dash. first check the fuse second check the headlight control switch.
Your shift linkage may have slipped or become loose. Check your linkage.
Check under the steering column. There is also few wires attached to the starter. This may also give you trouble, because they tend to break.
check you belt
try a local parts store some of them read the codes for free and will reset them for you otherwise you have to take it to a garage.
The cheapest way to find out what is wrong with your car is to check the little things before you start spending money. Check for bad fuses, check your battery if it's dead, check if you have enough oil in your car or even enough gas in your car to start it up, definitely check the spark plugs if their bad since you have a older car, air filter. if your car has nothing wrong with those minor problems then your going to have to go to your nearest auto store and ask them what can go wrong in a Chevy Caprice classic.
check for a spark from you r#1 cylinder and if it is fine then it is fuel related. If it's not fine check your distributor cap for wear
check all brake bulbs a filiment may have shorted out
Check the fuse.jr