andy4x4

So i have a 1987 Toyota pickup and sense i bought it the brights never have worked, the low beams come on, but when i switch it to brights they turn off. the dash light comes on, i replaced the relay and still no change, i have power to the right sockets when i checked at the wiring pigtail. the only thing i can think of is the column switch, but i don't want to spend a 100 bucks and the time getting to it and that not be the problem, any ideas on what to try?

Terrys87

iTrader: (1)

Here is how I fixed mine.>>> https://www.yotatech.com/forums/f199...l#post51724567

Co_94_PU

iTrader: (-1)

It's important to understand the system is switched ground. This means there will always be power at the plug. You'll need to test for ground, not power.

Does the flash mode work, eg pull back on the lever. This will verify it's not the bulbs and isolate it to a switch issue. At which point you can decide to clean and refurbish it or replace it.

wyoming9

iTrader: (1)

Have you checked it is not that the bulbs are burnt out on high beam??

pcola

had the same problem with my 88' 4x4 i could pull back and flash my high beams but if pushed forward my lights would go out. i went and bought a new switch and same thing errr. then i removed my steering wheel "very easy" and found the contact for high beam was rusted, so i took a cheap fingernail file and cleaned the contact. i was amazed how simple the fix was "also did the same thing for my dome lamp" both are still working great! hope this helps....

pcola

guess i should have took notice at "terrys87" lol! i think thats the same post i found awhile back to fix mine. great thread Terrys87!!!! thank you

RAD4Runner

Correct, pull to flash uses different contacts from turning dimmer switch to high beams. If pull to flash works for both highs beams, but turning dimmer-combo switch to highs does not, very probable it's the dimmer-combo switch contacts (shown on link on Terry's post.).

Poor stock circuit design makes high current (approx 10Amps) for headlight go through switch contacts causing:
1) Contacts to get pitted/oxidized pre-maturely, AND
2) Too much resistance and voltage drop in wiring,
3) Also, ground in stock wiring goes from bulb, to cabin to dash, to dimmer-switch, back to engine compartment, to ground inside right-hand fender. That also means additional resistance in wiring.

(2) and (3) lead to dim lights on these early gens.

Adding relays closer to battery and headlights to carry 10-amperes, as in the H4 conversion harness, will prevent future problem.

Terrys87

iTrader: (1)

Thanks pcola..Somehow if there is a problem with these trucks, I will wind up with them. I tried to make my 88 Runner build thread to show on the first post how I went about and fixed things. I am constantly adding more info to it as I find it. Not always the best pictures or descriptions but hopefully enough information to someone stuck in a situation headed in the right direction. Thanks again for the compliment.

Rad4Runner..I sure wish I had your ability to follow an electrical diagram the way you do. You have the ability to take a complex circuit and make it understandable. Great job!!