01 headlight problem

[huyroy]

So here's my problem. Both headlights are super dim. I can tell that it's on but it's like no lights when driving in the dark. I tested voltage and the passenger side connector seems to be doing what it's suppose to do but I have no ground on the driver side. With one bad ground, does it cause both headlights to be dim? Just thought each side is independently of the other. Anyways, does anyone knows where the driver side ground leads to? all the wires are all wrapped up and I am not sure where to follow. Also high beam works on passenger side and not driver side. I'm not sure if that means anything but yeah.... any help would be greatly appreciated. Fuses are all good.

 

[nissanh]

Correct me if I am wrong. The common wire in the head light wire plug is the positive and low and high beams are selected by sending the ground signal (negative) to the light bulb.

 

[TheDurk]

Correct me if I am wrong. The common wire in the head light wire plug is the positive and low and high beams are selected by sending the ground signal (negative) to the light bulb.

Only on non-DRL trucks. He is in Canada, so he HAS to have DRL's. Therefore common ground and switched positive.

My guess is OP is stuck on Daylight Running Lights. This is not easy to troubleshoot, but [MENTION=102597]IBallEngineer[/MENTION] and I have a track record of doing it. Get yourself a DMM and a test light, and give us exact model and year and we can help you, but expect it to be somewhat involved. Also confirm truck was born a Canada model and is not a US retrofit from '99 or earlier when US trucks did not have DRL's. That would complicate things.

Here is what the circuit looks like on a 2002--what I call a non-trivial exercise. Last time it turned out to be the car-off cut-out circuit in the gauge cluster, but it could be anything.

Have you tried swapping bulbs side-to-side to see if that high beam problem moves? Both sides of the light circuits join up close to the lights, so any one-side problem is fuse, bulb, socket, or a short run of wire. Let's rule out bulb first.

Also, check the small DRL fuse as well as all four headlight fuses. Do not trust a visual check, use a test light on both ends of fuse or swap in a known good fuse.

 

[IBallEngineer]

Only on non-DRL trucks. He is in Canada, so he HAS to have DRL's. Therefore common ground and switched positive.

My guess is OP is stuck on Daylight Running Lights. This is not easy to troubleshoot, but [MENTION=102597]IBallEngineer[/MENTION] and I have a track record of doing it. Get yourself a DMM and a test light, and give us exact model and year and we can help you, but expect it to be somewhat involved. Also confirm truck was born a Canada model and is not a US retrofit from '99 or earlier when US trucks did not have DRL's. That would complicate things.

Here is what the circuit looks like on a 2002--what I call a non-trivial exercise. Last time it turned out to be the car-off cut-out circuit in the gauge cluster, but it could be anything.

Have you tried swapping bulbs side-to-side to see if that high beam problem moves? Both sides of the light circuits join up close to the lights, so any one-side problem is fuse, bulb, socket, or a short run of wire. Let's rule out bulb first.

Also, check the small DRL fuse as well as all four headlight fuses. Do not trust a visual check, use a test light on both ends of fuse or swap in a known good fuse.

And by somewhat involved, he means tracking down connectors and exact terminals. And of course, testing circuits and giving us the information.
:couch2:

 

[huyroy]

Its a 2001 SR5 and yes it is a canadian car. I've tried switching bulbs and even putting in new bulbs but no difference. Thanks for replying as this electrical problem is very confusing.

 

[TheDurk]

Its a 2001 SR5 and yes it is a canadian car. I've tried switching bulbs and even putting in new bulbs but no difference. Thanks for replying as this electrical problem is very confusing.

OK. Not bulbs. Then switch left and right high beam fuses. Also, did you check that 7.5A DRL fuse? If that is blown, you will be stuck with only DRL's, so that would be the nice easy answer.

The bad news is I have headlight diagrams for the 2002 and 2000 4Runners, but not 2001. We are going to have to track that one down as the DRL circuit changed every year. If anyone out there can help it would be appreciated.

EDIT: It looks like 2001 and 2002 may be identical--at least the method used for disabling the DRL's is identical and so is the p/n for the combination meter so let's proceed using the 2002 I posted--especially since I can't find the 2001 by Googling it.

Easy question, what happens when you pull the stalk and try to FLASH the lights?

 

[huyroy]

I checked the DRL fuse, it's still good. This started a few months ago with just the one side but then the other side is bad too now.
When i pull the stalk the high beam flashes but only on the passenger side. I'm really not too good about this electrical stuff so please take it slow . If all fails I'm just gonna buy an HID kit with a relay harness and call it the day. I tested it out with one and it works. But would be nice to get down to the problem still. I really appreciate your help

 

[TheDurk]

I checked the DRL fuse, it's still good. This started a few months ago with just the one side but then the other side is bad too now.
When i pull the stalk the high beam flashes but only on the passenger side. I'm really not too good about this electrical stuff so please take it slow . If all fails I'm just gonna buy an HID kit with a relay harness and call it the day. I tested it out with one and it works. But would be nice to get down to the problem still. I really appreciate your help

Did you try swapping the left and right high beam fuses? Do you have a test light or DMM (digital multi-meter)? Because it's time to start tracing circuits. We will need to get access to the wires to the headlight stalk. Can you do that? If you could check and list the colors of all the wires on that plug by pin number it would help us be sure we have the right wire diagram before we go any further.
[MENTION=102597]IBallEngineer[/MENTION] I am leaving for Boston tomorrow AM for a few days. Can you put down the popcorn for a few days and run this one?

The pin numbers are shown on plug c13 on Page K here:

 

[IBallEngineer]

Of course I'll do all I can. I have to admit I haven't been all the way involved. But I'll read the posts again and help him. Have fun in the land of Sawx fans [MENTION=10169]TheDurk[/MENTION].

:ranger:

 

[chimpy]

Do the DRL's run in series and then switch to parallel when headlights are switched on?

 

[IBallEngineer]

Do the DRL's run in series and then switch to parallel when headlights are switched on?

No, they never run in series. The only thing that changes when the headlamps are switched on is the ground source, (direct instead of through the DRL relay/controller)

 

[chimpy]

I know that some GM had the headlamps in series (relay 30 and 87A)for the DRL's and headlamp switch on to parallel (same relay 30 and 87) but didn't know if Toyota did this. Thanks!
Guess it would help if I look at a wiring schematic, huh?

 

[TheDurk]

Of course I'll do all I can. I have to admit I haven't been all the way involved. But I'll read the posts again and help him. Have fun in the land of Sawx fans [MENTION=10169]TheDurk[/MENTION].

:ranger:

Yeah, I have to take the Yankees hitch cover off or they cut me off and refuse to let me in when I signal--not that they are much better without it. I can't really see wire diagrams on my phone but I'll read the posts..

 

[huyroy]

Sorry been busy and havent got the time to play around with the 4runner but yeah i managed to take some pictures of the connectors today. the color of the wires arent even the same as what they say in the haynes book. Not sure which is which .

 

[huyroy]

I forgot to mention, first picture is drive side, second is passenger

 

[TheDurk]

Well, they DO match the Toyota wiring diagram I posted. You actually have the unmitigated gall to first consult stinkin' Haynes rather than the wisdom of a random poster on the internet?

You can also go by the position in the connector, instead of wire color, as it is universal for all H4:

Now PLEASE swap those left and right high beam fuses so we can move on to something else.

 

[IBallEngineer]

Well, they DO match the Toyota wiring diagram I posted. You actually have the unmitigated gall to first consult stinkin' Haynes rather than the wisdom of a random poster on the internet?

You can also go by the position in the connector, instead of wire color, as it is universal for all H4:

Now PLEASE swap those left and right high beam fuses so we can move on to something else.

Oh yeah, Haynes. I'm pretty sure he played Corner for LA Rayduhs back when Lester Hayes had stickum all over his hands.

What?

 

[huyroy]

swapped the fuses, nothing changes .

 

[IBallEngineer]

swapped the fuses, nothing changes .

[MENTION=109209]huyroy[/MENTION], ok I believe you. doesn't seem like a fuse issue. I want to clarify a few things because I get easily distracted.

1. You are absolutely positive you have no continuity to ground at terminal 3 of the RH(passenger) headlight connector with the headlights on AND off.

2. If that is true, you shouldn't have ANY lights at all, so can you recheck with highbeams on/off and with all off(engine running park brake off).

3. Just to confirm, highs work on RH, not on left.

4. Check ground circuit on LH side as well, in low/high and off.

5. If any of the ground conditions are not correct. I'd like you to check continuity from the headlight connectors to the DRL relay#4, T2. This is located on the right side of the dash. Let me know if you need the location diagram.

Write your findings down and then post, if [MENTION=10169]TheDurk[/MENTION] is done traveling, we can get this solved quickly.

:snacker:

 

[sebeck1]

This is the EXACT problem I am having. Did anyone figure this out? Both headlights are super dim and brownish. If it turn on the high beams only the passenger light comes on and it appears to be full strength. I have ohm'd out all of the fuses and they are good.