1994 4Runner both head lights, low beam, will not turn on. High beam turns on. Not sure where to start. Can some one give me direction based on the problem? The 10 amp fuse looks normal. The Head relay and Head fuses are located on the passenger side engine. Thanks for any help.

 

If you have high beams, the problem is not likely to be in the headlight relay or the two 10amp headlight fuses. That leaves the bulbs themselves, or the "combination switch" (stalk on the steering column). First, try "flashing" the lights (pull back on the light stalk). That powers both high and low together. You might need to do it with high beams on, so that you can check if they get brighter with the second filament.

If that does nothing, you might have a burned out bulb. Odd that they'd go out at the same time, but it's easier to check them than the switch, so I would start there. You can get to the back of the lamps without removing them. Remove the connector and check for continuity between all three pins.

If even one bulb is good, you'll need to check the stalk switch. The connector is 13 pins (row of 6 and row of 7). The high beams are on pin 6, and should be a red-green wire. The switch activates the high beams by GROUNDING the r-g wire, so you'll need to use your voltmeter to check that pin against a source of 12v somewhere.

 

i only have hight beams when i pull the stalk back towards me. What should i get when i push the stalk forward? I had already changed the bulbs , same problem no low beams. Thanks for you advice.

 

take the steering column covers off, look at the switch, i think there are sets of points in there that might not be making contact, this happened to me once, but i'm thinking i had low beam but no high beam: i cleaned the contacts up and that fixed my problem

 

additional information. Pushing the stalk switch forward is high beam, i get no high beam. In the middle, no low beam when turning on the lights. Pulling the stalk backwards, i get flash. So, combination switch ? Ground ?

 

Then how do you know you have no low beams? "Flash" turns on both high and low beams; as far as you know it's flashing the low beams. Or both.

Anyway, since you have now told us you've already checked (well, not checked, just replaced) the lamps, it's almost certainly in the switch. You can take the switch apart and "try" to clean it, but before I did that I'd test the leads for function. Then you'll at least know if it is the switch, and what part isn't working.

 

Only High beam filament (R-Y) gets grounded when flashing, so only high-beam flashes.

Most likely combination switch contacts HU to ED, HL to ED (5 to 13, 6 to 13)
LANMAN, BEFORE YOU INTO IT:

1) Turn headlight lowbeam on. You should hear, feel headlight relay click. You should have 12V at pin 3 of both bulb connector (wires red-white and red-black)
2) Jump pin 2 (Red-Green) of either bulb. Low beam should turn on. (slightly pull connector out enough (like this) to stick paper clip and contact the pin.
3) Jump Pin 1 (red-yellow) of either bulb. Low-beam should turn on.

If 2 and 3 worked as expected, check combination switch contacts HU to ED, HL to ED (5 to 13, 6 to 13)

 

I'd start by running 3000 grit sand paper through the contacts in the column.

 

And check contacts for proper alignment. And once fixed, do H4 harness conversion to fix poor headlight circuit design. Google "convoluted path 4crawler"



Example of defective switch that fellow member fixed