Hi all, I'm having an issue where my headlights on my late '85 runner (IFS) go out randomly while driving. If i click over to highbeams i have no issues. I don't know if it's a switch issue with the stalk or something else but thought i'd ask in case other's have had the same issues. Any suggestions?

 

If BOTH high beams consistently work and BOTH low beams intermittently do NOT work, yes, most likely it's because of bad contact between pins 13(white with black stripe going to ground) and 6 (red with green stripe going to negative side of your low-beam filament) of your dimmer-switch combo (stalk). PLEASE VERIFY WIRE COLORS WITH YOUR FSM. SCHEMATIC BELOW IS FOR 1986 TO 1988 MOREFUNNERS.




Above could be caused by the poor wiring that the trucks came with out of the factory. The stock wiring subjects dimmer combo contacts (meant ton only control - not switch loads) to high currents.
After you fix / replace your dimmer combo, if you want to precen above problem AND have brighter lights, I strongly recommend the H4 conversion. this is more essential than any housing or bulb upgrade. Most important if you plan to use high-wattage (90? 110W?) high beams.

 

Thanks for the schematic, I'm not all that well versed with electrical switches and connections, do you think fixing the switch is a good bet or should I just look to replace it? Any chance you might know what PN I'd need to replace it? I don't have a parts manual on this truck.

 

You may well be able to fix the switch just by cleaning/burnishing the contacts in the combo switch.

Several, including me, have reported good results.

 

When low beams go out do they go out for more than a fraction of a second - to give you chance to do some tests or do they go out then come back on right away?

If they stay out long enough:
1) Take voltage reading between pins 6 and 13. If there is more than zero volt while in low beam position and lights are still out, that confirms that contact is bad.
OR...
2) Short pin 6 to pin 13. If that makes them come back on consistently, yes, contacts are bad.

Probably pitted or corroded. IF you can find out how to take switch apart, you'll easily see if possible to fix the switch.

Our 87 Honda Prelude had same issue so I built up the pitted spot with solder and it worked again. However, because of the heavy load on contacts, it did not last very long. IF YOU USE H4 CONVERSION HARNESS RIGHT AWAY, contacts repaired that way would last longer - enough to give you time to save or shop replacement.

PN ------- STILL researching ---
Found the stalk on rockauto.com but that's not what you need. You need the one that the stalk inserts into. The one you actuate bu pulling stalk back or pushing forward.

 

Here is how I go about fixing my head light issues >>>> https://www.yotatech.com/forums/f199...l#post51724567 usually the contacts need cleaned.

 

I had exact same problem and ended up being the wire that runs from stalk through plug underneath steering column and to main fuse block under hood to headlight relay. I would lose the lights and hitting high beams would bring back. When they went out for good i discovered the wire was corroded/melted inside the harness under the front right fender. I had the harness plug under steering column melt the same wire on another tuck. I suspected bad grounds in both cases and after cleaning the grounds and repairing the wire neither occurred again. Maybe try checking continuity on the red wire going from headlight relay back to harness plug under steering column.

 

cleaning the switch contacts IS a good bet. i'd already installed the h4 conversion, but eventually the hi beams wouldn't switch on. i took the switch apart, used fine grit emery, and cleaned all of the contacts. did this on my 91 celica, too. lights function correctly now.

 

If your going to work on vehicles learn simple DC circuits makes it so much easier.

The Toyota wiring diagrams are some of best as for how the information is shown.

Get the EWD for your vehicle That is the first thing I get when getting another one.