Pelican Parts Forums - warning lights on, turn signals not working

I went to start up my car after a few minutes in the grocery store and i first noticed that my turn signals werent functioning.... Next thing i know the thermometer is high in the "red" zone, and my oil light is flashing. I stop the car, get out... the engine isnt remarkably hot, and the oil seems to be fine and Im showing oil pressure. Whenever I but my foot on the brake, the thermometer and gas gauge bounce... Ive heard that this is because of a bad ground. Where is this ground?

One last note: i have been repairing a rust hole in the battery compartment, and have been removing/placing my battery in a whole lot... so i didnt secure the contacts to the battery as snug as i usually do.

When i got home, all of these problems went away, except the thermometer was reading high, and still fluctuated with the pressing of the brake.

Thoughts....