93 sentra electrical problem

[93sentraclassicfl]

Hey everyone! I have a 93 sentra classic and am having some trouble with a couple of things, first. The rad fan won't activate when needed, I bypassed it so I know the fan is fuctional my question is , could it be the temp sensor and if so where is it located and can it be tested. Two, the tail lights. When I turn on the lights and press on the brakes both elements in bulb turn on activating the warning light in the dash. I have cleaned up all exterior connections but still no luck...thoughts? Also I should mention the car has sat for a long time , a few years. Any thoughts help or advise is greatly appreciated , Thanks