Troubleshooting: High Beams Do Not Work, Flash and Low Beams Work
(Putting this here for ease of finding later)
Troubleshooting: High Beams Do Not Work, Flash and Low Beams Work. Applies to 1984 to 1995 MoreFunners.
I have not actually done this work hands-on, so would appreciate if anybody could share pictures of switch and test points/pins.
Symptoms:
BOTH high beams do not work,
High beam flash works AND low beams work.
Turn headlights on. Make sure low beams come on.
Switch to high beam. Still no light, of course?
Find Pins 5 (Red-Yel Wire) and 13 (wht-blk) of dimmer combo switch . Jump 5 to 13. Got highs?
If you get high beam, it's bad contact between those 2 pins. You may be able to clean or fix.
However, the flaw in headlight wiring of that generation where current flows on thin wire over a convoluted path (ask 4crawler) and though the dimmer-combo switch will shorten it's life again.
If you still don't get highs, jump pin 5 directly to shiny, bare metal ground. Got highs? If yes, it's bad connection between pin 13 and ground.