Hi all,

So I've been having an issue with my headlights for the past couple weeks with no end in sight on a 1995 Tacoma. I've searched all the threads here and several other forums, all with great suggestions, just none of them worked for me.

The low beams do not receive power when switched on. High beams and the flash both get 11.6V at the connector when they're on, so they are working just fine. So far I've gone through all the usual culprits: replaced fuses, headlight relay, headlights, combo switch (both of which were tested and complied with the user manual for continuity across pins), and the only thing left is the wiring harness. Rather than dive into the mess of wires that join and bundle and disappear, I thought I'd ask for any advice anyone can provide first.

Also, another clue could be that the high beam dash indicator does not light up. Its a switched ground system, so maybe I'm having a ground issue when in the low beam position? No DRLs.

Any insight would be appreciated before I tear my hair out any further. I'm almost ready to just run a seperate set of wires for the low beams instead of ripping everything else out. Wiring diagram is attached. Thanks guys!

 

What transpired from when the low beams used to work and when they stopped working?

Low beam connector pin should go to 0 volts (ground) when turned on. The center/common pin will have 12 volts in all modes. Ground comes through the headlight/combo switch:
- http://www.4crawler.com/4x4/CheapTri...l#HarnessTypes

Might make sure the headlight bulbs and see if they match the pin-out of the connectors (high/low/common).
Also, high beam indicator light current path is through the low beam filament, so if no current flowing in the low beam circuit, no high beam indicator.

 

Nothing dramatic happened. One day I went to turn on the headlights and the lows didn't work. I'm getting nothing in the front connectors with the low beams on, even at the center connector, so that would make sense that I'm not getting the high beam indicator showing up. Sounds like no current flowing in the low beam circuit. Could I ground out the red/green wire (from the attached diagram) and see if maybe the ground is not functioning from the headlight/combo switch?

 

sounds like you need a new light stalk/switch mate if everything else is working and you have checked/changed the bulbs and fuses then i would defo say its new light stalk time. think they are a sealed unit on them so you cant clean up the contacts.

 

Yes, sounds like the combo switch. It should turn on the headlight relay to send 12 volts to the common pin in the headlight connectors, then in low beam mode, ground the low beam pin in the connector. The common pin should be 12 volts in low, high and flash mode. If it is turning off in low beam mode, then check for what signals out of the combo switch are changing. When I lost high beams, I watched the combo switch contacts as you switch from mode to mode and identified the ones that were changing in high beam me, then I found one of those were pitted:
- http://www.4crawler.com/4x4/CheapTri...eadlight_Combo

 

Did you try the above link from 4Crawler? If so did it fix your low beam problem?

 

one thing i just thought about.. when i didn't have low beams working and the highs where on i didn't get a high beam light on the dash. it could be that a bulbs blew and so that's why there not working, both of mine where blown and when i replaced they started working..

 

If you look at the high beam indicator circuit, it is current flowing from the headlight common terminal through the (off) low beam filament and back through the low beam wire to the high beam indicator and then to ground. So if both low beams are burned out, no current flows back to the dash and no high beam indicator. In logic terms, the "high beams on" indicator is actually a "not low beams on" indicator.