headlights on 92 tercel only work when held in the back high beam flash position. I replaced one lamp but still doesn't work.
You will most likely need to replace the turn signal/headlight switch (the stalk on the steering wheel). Even though the headlights only work in the high beam position, the fact that they work at all means it would not be the fuse or relay that is broken. You could also check fuses for any other component controlled by that headlight switch, such as turn signals or cruise control. Electronics are sensitive and I have actually seen cars where the cruise control did not work because a turn signal was burned out.