The temp and fuel gauges max out on a 1987 Toyota corolla the fuses were checked and are good How do you get the gauges working again?

these guages share a resistor. if the the resistor goes bad, in this case, stops resisting, the voltage increases and makes both guages shoot up. replace the guage assembly and your problems will be over. (you have to remove the combination meter and take it apart to fix this, its not particularly easy and you can cause more damage than its worth if youre not experienced with this type of repair)

Answer

you can just add a resistor from radioshack don't really matter what kind but just install in line with the guage ain't working but you need to have x-perience to this