No low beams, no high beams, electrical gremlins?!

[Cnellis80]

Yes, I searched using numerous different terms. Yes, I read any threads that had symptoms similar to what I am dealing with even if all criteria wasn't met. I lurk and read on this forum a lot, just don't post or comment. Please be nice LOL!

2000 4Runner Limited

Went to leave the other night and had no low beams, no high beams, no fogs (since no low beams), brights work when I pull stalk toward me, but will not stay on, no indicator light on dash for brights when pushed on but is when I pull toward me, also no parking brake indicator light now.

Tested the combo switch for lights and it tested good, DRL has been disconnected for a couple years and never had an issue, relays all test fine, voltage to relays all tests fine...until you go to insert a relay, any of them, then there is resistance of some sort and eventually falls to no voltage.

I have checked all major grounds in engine compartment and in driver kick panel so far. I cleaned all connections, dieelectric greased them and all were good prior, but now I know corrosion free as well. I have checked the headlights using known good ones- no change. I have used my meter and verified all fuses are good. I have changed relays with others even though current ones test good- no change. I have not tested the integration relay (Body control module I am assuming). Besides that or the combination meter, what else could it be? I have printed off EWD for headlight circuit, the power source diagram and ground point diagrams and am at a loss.

 

[brillo_76]

Do you have power at the connector of the headlights?

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[Cnellis80]

Power is being supplied to the relay but its ground signal is not there on the coil side. Therefore the relay will not energize and no power being sent to the headlight sockets. Relay responds as it should when given ground manually.

 

[brillo_76]

So you loosing the ground before the relay. Going to to have to trace the circuit via the ewd and see where you loose it.. So if you supply a ground to the relay everything will work?

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[19963.4lsr5]

I think you should always have a hot at the light bulb socket. All the switch does is ground one of the relays to light the bulb. It’s kind of funkie how the high beam indicator illuminated through the low beam filament when the high beam is on.


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[Cnellis80]

Yes, when manually grounded I had all lights working. Could not consistently get the same result though. Tried with stalk on, grounding relay manually lights would work, but when I would try the same exact test later, then they wouldn’t. For now we have the relays jumped out and headlights getting power straight from the battery to a carling switch inside. Even when the temporary switch is “off” my lights stay on at about 10%. Been unplugging lights at the socket when I’m not driving for the rest of the evening.

High beam indicator was showing with stalk pulled and toward the end of trying to chase down the issue, the high beam indicator was no longer, lost tail lights and marker lights as well. This is why we put a switch in for now so I could at least drive when headlights are needed. Voltage all tested fine a relay box under the hood, but as soon as you insert a relay into its home, voltage drops to half immediately, then no voltage at all.

Seems like the signal is getting lost somewhere that tells the relay to do its thing. I will go out and verify again whether there is power at the sockets or not.

 

[Cnellis80]

You can hear the clicking sound behind the glovebox when stalk is pulled toward you calling for brights to flash, but not when pushed forward to turn the brights on. Headlight relay is working, dimmer relay is the one not getting ground on the coil side. Combo switch inside tests good, even have a spare from a similar fiasco when I first bought this 4runner a few years ago. That switch also tests good and was swapped in to see if I got different results, no change.

 

[IBallEngineer]

\ Headlight relay is working, dimmer relay is the one not getting ground on the coil side. \

Good day! I have not had much time to help out but I'll give it a try if El Durko doesn't show up! I am confused by this comment. According to the EWD I am looking at, which I printed long ago and hand wrote (2000 w/DRL), the Dimmer relay is grounded by the DRL relay(Main), and it is POWERED by the Headlight Relay. If you read the headlight operation portion of the EWD it is confusing because, it doesn't follow the diagram completely, and leaves out some key parts. But let's not be so negative, OK? OK! Can you start by telling me what you did to disable the DRL's? Also you say you can ground the relay and it works, what exactly are you grounding? As you know the lo beams, high beams and DRL's are interdependent and all rely heavily on the MAIN DRL relay, as well as DRL #4. Ground for the Dimmer relay is supplied by the MAIN DRL relay according to my diagram. Look at the system outline and read it through while looking at the diagram so you can get a handle on how it works. You say you are not getting power to the headlights at all, so that indicates the HL relay is not providing it, either because it is not getting ground from the MAIN DRL relay, or an open circuit. I know its a lot to absorb, start by telling me what you did to disable DRL, and then we can start testing some circuits! Fair Warning though, I teach High School Auto shop these days and it takes MASSIVE amounts of my time during the week, so please be patient with me! Thanks!

:couch2:

 

[Cnellis80]

For testing sake, DRLs have not been deleted. I originally clipped the B-Y wire. I did this years ago and never had any issues with them until the latest $hit$how. Upon hooking the B-Y wire backup on the DRL module, I do get the bright indicator light on the dash when I pull that stalk toward me for brights, but nothing when I push the stalk forward. I also do not have dash lights and turning the dimmer knob was not the issue.

All of the relays are being supplied positive on the high amp and low amp, and the low amp switched coil side correctly. If we take a paperclip and jump from the high amp positive input to the high amp positive output on any of the relays, then all of the lights work correctly. All of these relays are automatically fed positive and the ground is switched. The problem we are having is the ground on the coil/signal side of the relay. We decided to go redneck the other night and just jump all of the ground signals together and then hook them to a switch in the dash that has the other side grounded. The problem ended up being that there is some back-feed coming up a circuit that allows some minuscule voltage to power my headlights just enough to where they are barely illuminated. We have not identified which circuit is causing this, but after looking at the EWD it's really hard to tell which way we should go. The common symptom is that we are not getting ground signal to the headlights, fog lights, and marker/parking lights.

I, myself, did the basic troubleshooting on this issue and once I got nowhere I called in my husband who troubleshoots and chases wiring on HVAC systems, GM vehicles, and many other things. His mind is blown at the Toyota EWD LOL!

His preference would be to remove all the Toyota wiring and run it all himself with home runs to every circuit with breakers in every one. My preference is to figure out where the issue is and get this back to working as it should.

I really appreciate y'alls help! If ever you are stumped on HVAC stuff, please hit me up and we can walk you through troubleshooting it.

 

[brillo_76]

Oh boy. I wouldn't be chopping wires out and replacing them. When tracing them you can verify the wires are good with continuity and verify they are not shorted to ground if they are positive wires. Plus verify the grounds are not shorting to positive.


I suspect switches, relays and bad grounds and unless you have critters chewing on your wires.


The electrical diagrams so you where all the wires go provided they vary slightly per year. So need to have the diagrams matching your vehicle year.

Granted it's going to some time to verify all the components in headlight circuits.


With time and patience, it can be found.

Without slicing and dicing.

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[Cnellis80]

Oh boy. I wouldn't be chopping wires out and replacing them. When tracing them you can verify the wires are good with continuity and verify they are not shorted to ground if they are positive wires. Plus verify the grounds are not shorting to positive.


I suspect switches, relays and bad grounds and unless you have critters chewing on your wires.


The electrical diagrams so you where all the wires go provided they vary slightly per year. So need to have the diagrams matching your vehicle year.

Granted it's going to some time to verify all the components in headlight circuits.


With time and patience, it can be found.

Without slicing and dicing.

Sent from my SM-A505U using Tapatalk

Slicing and dicing was not my idea LOL! I'm game to chase this down with some guidance. I've looked at many EWDs and the one for my 4runner is by far the most confusing.

 

[IBallEngineer]

Oh boy, lots to address here. First off I am sorry for the delay getting back to you, but such is life. Also, please do not start hacking up wires, U\unless you have a lot of experience in creating circuits made to last and understand ALL of the ramifications of doing so. In the end it should be less work to fix it than to re-engineer it.

You say you wired all the grounds together, Can you tell me which grounds exactly? I think the back feeding is probably the DRL diode on the ground side of the DRL relay #4. Either you are upstream with your ground or it is bad. But that is not the problem.

Can you start by telling me if you have power at the 7.5 DRL fuse AND at the head lamp connectors? This will tell us if the head lamp relay is functioning. For any of these tests to give meaningful results, make sure everything is connected in it's original format, not auxiliary switches in any way.

If you do not!! Mention me so I get the notification right away and I'll examine your results. Which would now involve the MAIN DRL relay.

If that checks out ok, check for ground at terminal 16 of the combination(headlight) switch, there should be ground ALL the time. If so, turn the switch on (low beams) and check for ground at terminal 13. This will confirm that the comb switch is working for low beams. You can check ground with the switch on at Terminal 14, this is the tail lamp circuit(AND dash lights).

If this does not check out, please mention me so I get notified, if it does, go to this next step.

Up to now we have been testing upstream of the Combination Meter, I know you said you swapped one in, but we must confirm what is happening before we blame other things. If you had ground at Terminal 13 of the switch, that supplies ground to the Red/Green stripe wire of the DRL relay #4(Terminal 3). Check at that terminal with the switch on, if ground is present, the Comb Meter is fine, if it isn't, we need to check Terminals 1 and 5 at the meter.

If Terminal 3 at the DRL relay #4 has ground with the switch on, then we go deep! Let me know how all this goes and I will try to respond as soon as I can. Follow these instructions carefully, write down your results, YOU can do this.

opcorn:

 

[Trekka]

Oh boy, lots to address here. First off I am sorry for the delay getting back to you, but such is life. Also, please do not start hacking up wires, U\unless you have a lot of experience in creating circuits made to last and understand ALL of the ramifications of doing so. In the end it should be less work to fix it than to re-engineer it.

You say you wired all the grounds together, Can you tell me which grounds exactly? I think the back feeding is probably the DRL diode on the ground side of the DRL relay #4. Either you are upstream with your ground or it is bad. But that is not the problem.

Can you start by telling me if you have power at the 7.5 DRL fuse AND at the head lamp connectors? This will tell us if the head lamp relay is functioning. For any of these tests to give meaningful results, make sure everything is connected in it's original format, not auxiliary switches in any way.

If you do not!! Mention me so I get the notification right away and I'll examine your results. Which would now involve the MAIN DRL relay.

If that checks out ok, check for ground at terminal 16 of the combination(headlight) switch, there should be ground ALL the time. If so, turn the switch on (low beams) and check for ground at terminal 13. This will confirm that the comb switch is working for low beams. You can check ground with the switch on at Terminal 14, this is the tail lamp circuit(AND dash lights).

If this does not check out, please mention me so I get notified, if it does, go to this next step.

Up to now we have been testing upstream of the Combination Meter, I know you said you swapped one in, but we must confirm what is happening before we blame other things. If you had ground at Terminal 13 of the switch, that supplies ground to the Red/Green stripe wire of the DRL relay #4(Terminal 3). Check at that terminal with the switch on, if ground is present, the Comb Meter is fine, if it isn't, we need to check Terminals 1 and 5 at the meter.

If Terminal 3 at the DRL relay #4 has ground with the switch on, then we go deep! Let me know how all this goes and I will try to respond as soon as I can. Follow these instructions carefully, write down your results, YOU can do this.

opcorn:

Hey, it seems the original poster has not been able to reply, but I am having a similar scenario.

The original owner had fog lamps installed after purchasing it and the installer ran splices on two wires from the Selector that go to the DRL main relay - Black with Red stripe and Green. The auxiliary switch simply shorts these two and power is then provided to the fog lamps. It looked factory, but once I opened the steering column and noticed the splices, it was obviously an afterthought. The installer used a mess of electrical tape and splices one would buy at the parts store. Personally, If I was Toyota, I would have crimped the wires to the auxiliary switch for the fog lamps.

Alas, ever since I've pulled out this auxiliary switch to replace it with one to match the KC high beams I installed to the grill, on a separate circuit + aftermarket relay, the DRL has been acting similar to how it was described by Cnellis80.

No high beams toggle, only flash when pulling switch towards wheel.
DRL lamps come on at 10% brightness, but do not go to full illumination when the switch for Lo-Beams is on.

Tail, dash, blinkers and hazards all work as I was expecting.

The DRL itself was never tampered with, no wires snipped only spliced and I've checked the fuses for continuity, but have not checked for their connection to ground. I removed and tested the relays with a desktop power supply, and so far no faults seem to exist with the relays. I do have voltage on the HEAD, FOG and EFI sockets.

Please let me know if you see this, and if you're still active - willing to help me pick up where these steps dropped off.

Thank you.

 

[jhams]

maybe check the fusebox?

 

[Trekka]

maybe check the fusebox?

I've done this several times over now. I am pretty confident the problem does not lie within the hot side as my headlights still come on, be it incredibly dim even with the Low-Beams and Hi-Beams combinator switch engaged.

 

[Trekka]

You say you wired all the grounds together, Can you tell me which grounds exactly? I think the back feeding is probably the DRL diode on the ground side of the DRL relay #4. Either you are upstream with your ground or it is bad. But that is not the problem.

I am trying to figure out where these diodes are in order to check this. I have partially taken apart the dashboard and so far cannot find the location of DRL Relay #4. Is it on the passenger side or the driver side? On some 4R 98-01 diagrams I see it behind the center registers, but in another thread it was stated to be behind the right-most A/C register. The passenger side? I peeked on this side and did not see it. I can not find decent diagrams for the locations of all the relay boxes.

Can you start by telling me if you have power at the 7.5 DRL fuse AND at the head lamp connectors? This will tell us if the head lamp relay is functioning. For any of these tests to give meaningful results, make sure everything is connected in it's original format, not auxiliary switches in any way.

Power is at the 7.5 A DRL Fuse, at the head lamp connectors and at the DRL resistor.

If that checks out ok, check for ground at terminal 16 of the combination(headlight) switch, there should be ground ALL the time. If so, turn the switch on (low beams) and check for ground at terminal 13. This will confirm that the comb switch is working for low beams. You can check ground with the switch on at Terminal 14, this is the tail lamp circuit(AND dash lights).

I have continuity when testing the combinator switch between the parking lights, and low-beams and high toggle + high flash. The switch seems completely functional.

Up to now we have been testing upstream of the Combination Meter, I know you said you swapped one in, but we must confirm what is happening before we blame other things. If you had ground at Terminal 13 of the switch, that supplies ground to the Red/Green stripe wire of the DRL relay #4(Terminal 3). Check at that terminal with the switch on, if ground is present, the Comb Meter is fine, if it isn't, we need to check Terminals 1 and 5 at the meter.

I want to test this next, but cannot seem to locate DRL Relay #4.

If anyone else has experience with this, please shoot a reply. I fear this is a little more involved than just the fuses.

Thanks.

 

[Trekka]

I want to test this next, but cannot seem to locate DRL Relay #4.

Well, I've located this relay. Pretty much exactly where IBallEngineer said it would be. Except when I was looking for a cluster, it was stand alone, housed by a big rubber boot. I pulled that sucker off and began testing.

On my bench power supply, the relay energizes and the contacts lock. HOWEVER, when probing terminal 3 and ground, I get 1.1Vs which tells me my issue might be with the diodes.

Now this is the troubling part. The EWD I got states the diode that connects Red/Grn to the wire harness is also on passenger side. The connection snakes behind the return register and blower for the A/C which means more disassembly ahead.

I am not exactly sure what I'm looking for with regards to those stand-alone diodes. Are they going to be housed within a connector, are they small, large? Do they bolt into the firewall along the back? The EWD claims the diodes will be on the top, yet the cable seems to go down and back.

If anyone has any photos or videos (I can't find anything) with what I'm looking for, it would be appreciated.

I will be going back to add photos to this thread of my progress.

Happy Trekking.

 

[Trekka]

Photos

Good morning,

I'm about to put this all back together so I can make it to work this week. I take it might be a few days before a true aficionado can respond to some of my questions before I go deeper into this project. For now a good 'ol bypass jumper will do. :wacko:

Anyway, starting here, this is DRL Relay #4 located on the passenger side below the A/C register. As you can see it's solitary and the wires whip around towards the firewall instead of going to the top side of the dashboard. If I trace the wire with my fingers it joins up with the rest of the harness.

 

[Trekka]

This is a photo of the stalk.

I removed the connector for the combinator switch and attached a blade probe to port #16. I ran through all of the pins and got the expected continuity according to the EWD. I double checked this switch this morning before re-assembling the stalk.

Those blue splices go out to the auxiliary switch deck to the left of the steering wheel to control the fog lights. These are NOT getting power even when I jump the DRL relay. The splices were buried in a wad of electrical tape. Sticking with this logic, I've covered them with a much neater bit of tape - you absolutely do not want to risk any accidental contact with the airbag connector.

 

[Trekka]

This is the DRL Main Relay - it is situated on this circuit board that vaguely reminds me of my old Nintendo systems.

My question here is if anyone of these diodes could be responsible for connecting the ground side of the DRL Relay #4 coil to the wire harness?