How do you fix cruise control on 1993 chevy lumina i think it could be a fuse problem but i don't know where it might be

Did you check the fuses? That is the usual culprit. Next would be the connections and then the cruise control itself...

The lighter in a Chevy Lumina can get lost easily if you routinely pull it from the socket to plug in electronic devices like GPS systems, cell phone chargers and laptops. If so, you need to replace it.

Well usually when the third brake light works and the others don't, the problem is in the turn signal switch. The center brake light is separate from the other two as far as circuits go.
The thing that puzzles me is the cruise. It could be something else, because the only way a faulty brake light switch would kill the cruise control is if the switch was stuck on.
I think I would check the circuits in and out of the turn signal switch.

Look for a broken vacume line chances are one has been broken if im not mistaken i believe your cruise control also operates on vacume you repair these it will fix your problem just trace the lines and see where they are broke at.

to get a cheap fix have a free fault code reading done
Then go to the wreckers /junk yards to get the failed part

You have a gas pedal your suppose to use that to drive.cruise control is designed to be used at highway speeds for longtrips. Do not use in bad weather like rain or snow. Your using it for steep hills and may have other issues going on causing the power loss. May need a tuneup and check hoses under the hood for damage

1993 chevy caprice
If the center brake light bulb goes out the cruise control does not work.
Did you try replaceing the bulb?

Check the switch above the brake pedal. This is the switch the turns off the cruise when you hit the brakes. Make sure it is adjusted properly to allow the cruise to come on.

It sounds like a faulty check valve, it is located inline with the cruise control vacuum line or the vacuum brake booster vacuum supply line.

first check the fuse for the cruise control