hey guys i bought a 93 toyota 4x4 pu. the headlights wont work when you turn them on. but if you hold the lever back with your hand the brights work. i checked all of the grounds and the relays are good. i tested the plug that goes to the headlight itself and all three terminals have power. we tested my buddies toyota and only two out of the three terminals have power. do you think its the main switch thats causing this to happen?

 

http://www.ncttora.com/fsm/1990-1995...i/hdlitusa.pdf

Yes. Neither high nor low beams will work if the relay is not closed, so the relay is working. Your headlight switch is probably not grounding the R-Y wire when you turn it on, but it is grounding the R-G wire when you "flash" the highs.

The reason you have power (+12v) on all three terminals is that you are connecting back through the other headlamp. The lamp has direct power from the relay through the R-W lead. When there is a headlamp in the socket (the other side in your case), the other two leads get +12v through the lamp. If you grounded one of those two leads, the lamp would light with high or low.

 

If I remember right Roger Brown has a write up about this on his site

 

could be you light stalk bud the switch might be sticky or worn out, i know on mine the light stalk and wiper stalk are one unit but is an easy job to change. i had an issue where i had dipped beam but high beam would only work if i held the stalk the solution for mine was change the stalk.