1985 4runner
I have been fighting with this issue for several years now but my head lights will not work. The brights indicator in the dash lights up when I turn the headlights on (which shouldn't be occurring) and the brights do work both when manually pressing back the switch and when engaging the switch. The headlight issue has kind of changed over the years and as I attempt repairs. For instance, my headlights didn't work for many years but my brights did. I lightly sanded the contacts and that would fix the issue - for about a day. Then I changed out the relay with a brand new Toyota one and both worked - again for about a day. Now my brights work but my headlights don't. I checked the headlight fuses and they look good. I even tried to order a new switch from Toyota (part number 84310-35190) and Toyota no longer has it in stock. I am eyeing some used combo switches on Ebay but before I go that route, does anyone have any last-minute ideas on this?

Thanks,
JARED

 

If I remember correctly, Toyota grounds the circuit to turn the lights on.

I'd look for a grounding issue at the switch and steering wheel. (might explain the hi-beam indicator too)

Find a wiring diagram.

 

Thanks Ed. I'll see if I can scrounge up a schematic and then once I find one see if I can understand it enough. I do know that everything looked good when I tore the switch apart and I cleaned everything very well including taking out the switch plate (where the small bb sized ball makes contact) and lightly sanding that as well.

 

86 wiring diagram in this thread.

https://www.yotatech.com/forums/f131...h-beam-194102/

bad ground does explain the hi-beam indicator

 

Thanks again Ed. So if I am reading the information correctly, the issue is that when I apply the headlights, grounding is not occurring and the contacts in the switch cannot complete the circuit. So, I will tear apart the switch, again, and see if something came loose. I don't think the issue is at the battery as indicated in the post you sent.

 

The grounding problem may not be IN the switch but from the switch to ground.

 

In a nutshell: Your high-beam flash works, and normal high-beams work, but not low-beams?
Most likely bad switch contact. The earlier generation (1980's to U.S. model 2002, IIRC) headlight circuit is poorly-wired FROM THE FACTORY (ask 4Crawler). That causes it to be dim and to subject the switch contacts to unnecessarily high current. Switches like that should only carry relay coil current, not load current.

Quick Check:
Turn headlight switch on.
Jump pin 1 of headlight connector to ground. (pull connector apart just enough to you can slip a paper clip or a very thin multi-meter probe and contact pin 1.
If you feel comfortable diving deeper into the wiring, Jump Pin 6 of dimmer switch to pin 13 or ground.
Either of the above should turn low-beam on.
Please report back.

VOLTAGE CHECKS ON NORMALLY-FUCNTIONING HEADLIGHT SYSTEM

More detailed Headlight Troubleshooting (schematic is of 1988 but same concept from 84 to 1988. Pls double-check wire color code):
https://www.yotatech.com/forums/f116...ooting-302108/

 

So I wanted to close the loop on this (no pun intended considering the grounding issue I seemed to be experiencing) and thank everyone who provided insight. As it turns out, it was a ground issue and I only discovered this by buying another turn signal that I found on ebay. Once I took off my original one that was experiencing the issue, I looked at the back of it and discovered that a soldered wire had come loose. I still connected up the one I found on ebay as it looked like it was in pretty good condition and it works just fine. So, once I re-solder that wire, I'll have a spare.

Thanks again!

JARED