No High beams... need help

Guys, I have a 1994 pick-up. High beams work if you flash the switch but not in the on position...they just go out. I've replace head light relay, the light switch and still nothing. Any ideas and where on line can I find a wiring diagram?

 

Thanks for the link. I replace the column switch and still nothing. Is there anything else in the column i'm missing?

 

No problem thanks again.

 

I did see that. Ya think thats the dimmer knob on the dash for the dash lights cause thats the only dimmer i know of?

 

I replaced the whole combination switch which included the turn signal and wiper switch. This mysterious dimmer switch....i dont think my 94 has one?

 

Yeah, I replaced that already....I can flash high beams and the blue indicator light comes on but throw it in high beam mode and they go out....I'm at a loss.

 

A hypothesis:
If it's not the switch, then maybe it's the power. When you pull back on the stick to flash your high beams the low beams stay on. I don't know how the lights are wired, but it's possible that your high beams are being power by the low beam circuitry. When you put the stick forward to keep your brights on, the power to the low beams is cut. You could easily test with a continuity tester, just disconnect the battery first.

 

No it was off another truck. I hate to buy another new part and have it not work as you probably know you cant return electrical parts.

Thanks for that explanation...guess I'll start probing!

 

Unless there's an ECV/ computer for the lights, just use a continuity tester and trace the circuit until you find the break.

 

You can also check the switch easily, again, with a continuity tester.

Multimeters are pretty cheep and very useful

 

I'll try and get to it today. I'll post if and when I figure it out. Thanks again for all the help.

 

Turned out it was the switch...resistance was high. Strange that the other switch I tried did it too. Replaced it and all is well. Thanks again guys for your help.