Battery and brake light will not go off

First it think you may need to check your drive belt,if it is good,may need to check battery,alternator,brke,s light would be one to come on when power is low,i would think.

You may just remove your positive cable for a few minute,s and reset ecm,may fix your problem,but if light,s return i would think it is your belt,alternator,or battery.

I disconnected the ground to the battery and hooked up my multimeter on the "Amperage" reading. It has a 20 amp capacity, but even a 10 amp will do. Make sure no lights are on. The reading should be .005 or so amps. This is powering the clock, etc. If you have a consistent .5 or higher reading, then you need to start disconnecting fuses. When the reading drops to the .005 range when you pull a fuse, then that circuit is causing a load it shouldn't. I found that my fog lamps were causing a .9 amp drain when EVERYTHING was off. Interesting. It was draining my battery below 12 volts. This is when the battery light AND the parking brake light was staying on. Soooo....try this troubleshooting technique and see what happens.

I just had the same issue and it turned out my alternator is bad. I've replaced 3 in 3 years on my 2005 santa fe gls with 3.5 engine and it has to be your alternator. In my case when my rack n pinion steering axle went out I got brake fluid in the alternator and shorted out the voltage regulater . So make sure your car isn't leaking fliuds on yours when you replace your alternator. Its a 4 hour minimum job just for labor on these cars. Dumb design for repairs. Good luck