Headlights won't turn on…where are my electrical people?

[Fishwerks]

Alright folks, I don't usually post questions because most things have been covered, but I have a weird one here. I was wiring up my Contura V switches, one for my Hella windshield lights, the other for my Hella micro de fog lights (aka not factory installed, but close). Here is a picture of the pins on the Contura V switches for those who don't know:

I had the switches working, but the dependent LED (comes on when the accessory is on) was not very bright for my fog light switch compared to the windshield light switch, so I stuck an add-a-circuit with a 10 amp fuse in one of the blanks in the interior fuse block and put it on the #2 pin on the switch to see if it would be brighter than the incoming wire that tapped pin 11 in connector C13 which plugs into the headlight stalk (from instructions on wiring the fog lights when I installed them a while back). Pin #3 on the Contura V switches goes to pin 10 in connector C13. I hit the switch, smelled like hot plastic (not a good sign) almost immediately and the fogs didn't turn on so I switched it off.

Reconnected pin #2 on the switch to the wire that goes into pin 11 of connector C13 and now the headlights won't turn on. The high beams don't work when I push the stalk forward (for constant brights), but they do work when I pull the stalk back (like to flash someone). Weird part is, if I have the vehicle running, when I pull the stalk back to flash the high beams, the low beams will stay on afterwards. The fog lights will not turn on when the low beams stay on after flashing the brights.

Obviously, I sent too much current through the circuit and something is fried since it smelled like electrical fire, but it is not bulbs, fuses, or relay since the high beams work to flash and then the headlights stay on after. I pulled the steering wheel cover and there aren't any wires that are apparently melted.

I'm thinking I fried the stalk somehow? Turn signals still work, but headlights and constant brights do not.

Any other ideas? I could find another working stalk and see if it solves the problem, but that won't happen tonight, so I figured I'd see if anyone had ideas.

 

[TheDurk]

I won't even look at this until you specify whether your rig has DRL's or not. It makes all the difference in how you hook these up. DRL 4Runners have headlights with switched hots, non-DRL 4Runners have switched grounds. I get a headache looking at it and thinking about it two different ways. Plus it's two different circuit diagrams.

 

[IBallEngineer]

Alright folks, I don't usually post questions because most things have been covered, but I have a weird one here. I was wiring up my Contura V switches, one for my Hella windshield lights, the other for my Hella micro de fog lights (aka not factory installed, but close). Here is a picture of the pins on the Contura V switches for those who don't know:

I had the switches working, but the dependent LED (comes on when the accessory is on) was not very bright for my fog light switch compared to the windshield light switch, so I stuck an add-a-circuit with a 10 amp fuse in one of the blanks in the interior fuse block and put it on the #2 pin on the switch to see if it would be brighter than the incoming wire that tapped pin 11 in connector C13 which plugs into the headlight stalk (from instructions on wiring the fog lights when I installed them a while back). Pin #3 on the Contura V switches goes to pin 10 in connector C13. I hit the switch, smelled like hot plastic (not a good sign) almost immediately and the fogs didn't turn on so I switched it off.

Reconnected pin #2 on the switch to the wire that goes into pin 11 of connector C13 and now the headlights won't turn on. The high beams don't work when I push the stalk forward (for constant brights), but they do work when I pull the stalk back (like to flash someone). Weird part is, if I have the vehicle running, when I pull the stalk back to flash the high beams, the low beams will stay on afterwards. The fog lights will not turn on when the low beams stay on after flashing the brights.

Obviously, I sent too much current through the circuit and something is fried since it smelled like electrical fire, but it is not bulbs, fuses, or relay since the high beams work to flash and then the headlights stay on after. I pulled the steering wheel cover and there aren't any wires that are apparently melted.

I'm thinking I fried the stalk somehow? Turn signals still work, but headlights and constant brights do not.

Any other ideas? I could find another working stalk and see if it solves the problem, but that won't happen tonight, so I figured I'd see if anyone had ideas.

I highlighted the part above because I don't know how you wired your fog lamp. But I think the problem is right there. Pin 11 on connector 13 is the ground side of the fog lamp relay. When you applied power to pin 11, and then turned on the fog lamp switch, you created a dead short to ground. You should have blown the 10a LH lo beam fuse, but if you shut it off quick enough, maybe it wouldn't, maybe.

Also, does your truck have Daytime Running lights? That uses a relay, which is something of an ECU even though Toyota doesn't call it one. Coincidentally pin 11 grounds through that relay.

I agree with you, you probably fried your combination switch(stalk). But in the immortals words of Dr. Evil. NEED MORE INFO, throw me a bone.

Can you share the schematic of the a/m fog lamps? Just to start. Lots of things to look at here, but if you got another stalk, try it!

:couch2:

 

[Fishwerks]

I won't even look at this until you specify whether your rig has DRL's or not. It makes all the difference in how you hook these up. DRL 4Runners have headlights with switched hots, non-DRL 4Runners have switched grounds.

It has DRLs (2000), but I pulled the plug apart in the engine bay so they don't turn on if that makes any difference.

 

[IBallEngineer]

When you applied power to pin 11, and then turned on the fog lamp switch, you created a dead short to ground. You should have blown the 10a LH lo beam fuse, but if you shut it off quick enough, maybe it wouldn't, maybe.


:couch2:

OK, sorry, I must be high. You applied power to a ground circuit, but after the load, so it wouldn't blow the lo beam fuse. I should have blown your add-a-short circuit fuse though. Heh.

:couch2:

 

[Fishwerks]

I highlighted the part above because I don't know how you wired your fog lamp. But I think the problem is right there. Pin 11 on connector 13 is the ground side of the fog lamp relay. When you applied power to pin 11, and then turned on the fog lamp switch, you created a dead short to ground. You should have blown the 10a LH lo beam fuse, but if you shut it off quick enough, maybe it wouldn't, maybe.

Also, does your truck have Daytime Running lights? That uses a relay, which is something of an ECU even though Toyota doesn't call it one. Coincidentally pin 11 grounds through that relay.

I agree with you, you probably fried your combination switch(stalk). But in the immortals words of Dr. Evil. NEED MORE INFO, throw me a bone.

Can you share the schematic of the a/m fog lamps? Just to start. Lots of things to look at here, but if you got another stalk, try it!

:couch2:

Truck has DRLs, yes.

The fog lights came with wiring instructions for dummies (aka perfect for me). I don't have a wiring diagram, but the instructions don't provide one. It says "Locate and remove connector C13…locate green/black wire in pin location 10 of connector C13 and splice supplied wire of same color…locate red/black wire in pin 11 of connector C13 and splice supplied wire of same color…" then you take those two wires to the switch. Super easy.

OK, sorry, I must be high. You applied power to a ground circuit, but after the load, so it wouldn't blow the lo beam fuse. I should have blown your add-a-short circuit fuse though. Heh.

:couch2:

This is why I am confused that the headlights won't turn on now. I don't see how the headlights would even be affected, unless I partially blew up the stalk.
:noidea:

 

[TheDurk]

It has DRLs (2000), but I pulled the plug apart in the engine bay so they don't turn on if that makes any difference.

Yeah, it makes a big difference. I was recently working with another poster with a similar problem. He didn't want to do the diagnostics and ended up at a dealer.

First things first. Did you check the 7.5A DRL fuse? Believe it or not, without power to that fuse, you can't turn the DRL circuit OFF and turn the headlight circuit ON...With DRL's disabled, that means you would have no headlights at all, but the Hi flash would work.

BTW, don't waste your time and mine just looking at fuses. Use a meter, test light or swap with a known good fuse.

This is the closest wire diagram I have, which is a 2002 w/DRL.

 

[IBallEngineer]

As Durk said, HUGE difference. Totally different schematic. Disconnecting the lights themselves won't do a thing to save you. In the diagram he posted, you can see TWO DRL relays, one is a traditional Bosch type 4 pin, the other is a monster. I don't have DRL and have never examined this particular system, but it looks to be a mini body ecu type of nightmare. Maybe not. NEED MORE INFO to troubleshoot this though. I didn't look close, but if the diagram he sent has the "system outline" page, you need to read it. Then read it again, then talk about it with your friends, then commit it to memory, then come back and ask questions. By that time, we both might understand it!

:couch2:

 

[TheDurk]

As Durk said, HUGE difference. Totally different schematic. Disconnecting the lights themselves won't do a thing to save you. In the diagram he posted, you can see TWO DRL relays, one is a traditional Bosch type 4 pin, the other is a monster. I don't have DRL and have never examined this particular system, but it looks to be a mini body ecu type of nightmare. Maybe not. NEED MORE INFO to troubleshoot this though. I didn't look close, but if the diagram he sent has the "system outline" page, you need to read it. Then read it again, then talk about it with your friends, then commit it to memory, then come back and ask questions. By that time, we both might understand it!

:couch2:

Yeah, it's a hairy ball buster of a circuit. But if he can confirm good DRL fuse, I'll give him the voltage or ground states needed at about ten points for Highs to come on. If he can check if these are present, I think we can nail down where the fail is...assuming I've got it right. This is not a simple troubleshoot.

 

[Fishwerks]

Yeah, it makes a big difference. I was recently working with another poster with a similar problem. He didn't want to do the diagnostics and ended up at a dealer.

First things first. Did you check the 7.5A DRL fuse? Believe it or not, without power to that fuse, you can't turn the DRL circuit OFF and turn the headlight circuit ON...With DRL's disabled, that means you would have no headlights at all, but the Hi flash would work.

BTW, don't waste your time and mine just looking at fuses. Use a meter, test light or swap with a known good fuse.

This is the closest wire diagram I have, which is a 2002 w/DRL.

I don't think it's the DRL fuse (or a headlight fuse), as the low beams will turn on after flashing the brights (pulling stalk backwards), but only when the vehicle is running. For good measure I swapped the DRL fuse with a new 10A fuse (didn't have any 7.5A around) to see if they would come on normally, no go so I put the 7.5A back in. Thanks for the diagram, I'll look it over.

As Durk said, HUGE difference. Totally different schematic. Disconnecting the lights themselves won't do a thing to save you. In the diagram he posted, you can see TWO DRL relays, one is a traditional Bosch type 4 pin, the other is a monster. I don't have DRL and have never examined this particular system, but it looks to be a mini body ecu type of nightmare. Maybe not. NEED MORE INFO to troubleshoot this though. I didn't look close, but if the diagram he sent has the "system outline" page, you need to read it. Then read it again, then talk about it with your friends, then commit it to memory, then come back and ask questions. By that time, we both might understand it!

:couch2:

I already had the DRLs disabled before this wiring endeavor, sorry if that was confusing. And I will read that diagram, she's a doozy.

Thanks for the help so far guys.

 

[TheDurk]

I don't think it's the DRL fuse (or a headlight fuse), as the low beams will turn on after flashing the brights (pulling stalk backwards), but only when the vehicle is running. For good measure I swapped the DRL fuse with a new 10A fuse (didn't have any 7.5A around) to see if they would come on normally, no go so I put the 7.5A back in. Thanks for the diagram, I'll look it over.



I already had the DRLs disabled before this wiring endeavor, sorry if that was confusing. And I will read that diagram, she's a doozy.

Thanks for the help so far guys.

OK. Well, there is switching going on on both sides of the high beam filament. If we could limit our search for a fail by confirming which side of the filament is not in the needed state, we cut our task in half. So I would suggest you see which you are missing at the bulb when ignition is ON and Stalk is at HIGH: 12V+ or ground.

I don't know your skill level, so if you don't know how to do this, just ask. This may help:

The COMMON terminal needs ground, and the HIGH terminal needs 12V+. Presumably, you are missing one of those, if not, it's a dead bulb.

 

[nor_cal51501]

My .02 on this…I am putting money on the fact that your DRL "ECU/relay" shorted out. Even with it is disabled, it is still active as a pass through. If you were to short it out, your brights would still function as you said they did.

 

[TheDurk]

My .02 on this…I am putting money on the fact that your DRL "ECU/relay" shorted out. Even with it is disabled, it is still active as a pass through. If you were to short it out, your brights would still function as you said they did.

Possible, but there are other possibilities. If we figure out the exact fail, and it is the DRL ECU, we can possibly just by-pass it, as he doesn't use the DRL's.

 

[nor_cal51501]

Possible, but there are other possibilities. If we figure out the exact fail, and it is the DRL ECU, we can possibly just by-pass it, as he doesn't use the DRL's.

Bypassing it may be possible, from what I've read I don't think its possible and or no one has done it that I have seen. I hope it is possible though because the DRL module is expensive, so used is really the only option. And the factory fogs go through the DRL ecu/relay also so that would explain the lack of functionality on his fogs initially also, well…with the exception that OP'ers wiring was/is correct.

 

[IBallEngineer]

Bypassing it may be possible, from what I've read I don't think its possible and or no one has done it that I have seen. I hope it is possible though because the DRL module is expensive, so used is really the only option. And the factory fogs go through the DRL ecu/relay also so that would explain the lack of functionality on his fogs initially also, well…with the exception that OP'ers wiring was/is correct.

Of course it is possible! He doesn't use the DRL anyway, and his fog lamps are not factory. Even if they were original fog lamps, it could still be bypassed very easily. It would not be my first choice because it is cheating, maybe even leaning toward butchering. But my truck has a Chevy engine, and I've butchered, cheated, and lied to it many times. So who am I to say no? But let's troubleshoot it first before we condemn it.

:couch2:

 

[Fishwerks]

OK. Well, there is switching going on on both sides of the high beam filament. If we could limit our search for a fail by confirming which side of the filament is not in the needed state, we cut our task in half. So I would suggest you see which you are missing at the bulb when ignition is ON and Stalk is at HIGH: 12V+ or ground.

I don't know your skill level, so if you don't know how to do this, just ask. This may help:

The COMMON terminal needs ground, and the HIGH terminal needs 12V+. Presumably, you are missing one of those, if not, it's a dead bulb.

With the engine running, headlight switch ON and stalk at HIGH I get +12V at the high terminal and good ground at COMMON on both headlights.

Without the engine running, but ignition at ON and headlights on with stalk pushed to HIGH, I don't get +12V at high or low and I don't get a ground at COMMON either.

I'm 95% that I'm using the multimeter correctly to test ground (ohms = 0) and +12V (DC) since I get good readings with the engine running…. I'm putting the negative cable from the multimeter on a chassis ground and the positive cable on each pin for the headlight, switching from DC to ohms for +12V and ground, respectively.

 

[TheDurk]

With the engine running, headlight switch ON and stalk at HIGH I get +12V at the high terminal and good ground at COMMON on both headlights.

Without the engine running, but ignition at ON and headlights on with stalk pushed to HIGH, I don't get +12V at high or low and I don't get a ground at COMMON either.

I'm 95% that I'm using the multimeter correctly to test ground (ohms = 0) and +12V (DC) since I get good readings with the engine running…. I'm putting the negative cable from the multimeter on a chassis ground and the positive cable on each pin for the headlight, switching from DC to ohms for +12V and ground, respectively.

No. Don't use ohms for ground. Use DC volts between battery positive and the COMMON (plug-side, obviously). If that gives you 12V, THAT's a good ground. I actually prefer a test light probe for this, so you are running some real current through there. In theory you're right. But trust me, ohms will mislead you here.

And do I understand that the lights illuminate in the first case, but not in the second? So you can actually drive and the headlights work? Or am I confused?

 

[IBallEngineer]

I don't want to confuzzle anyone so I'll defer to The Durk and only interject if I think something needs clarification.

I'll be in the peanut gallery!

:couch2:

 

[TheDurk]

I don't want to confuzzle anyone so I'll defer to The Durk and only interject if I think something needs clarification.

I'll be in the peanut gallery!

:couch2:

Happy to have you looking in and feel free to comment--there is more than one way to skin a cat and some are better than others. I won't claim I have this circuit fully modeled in my head--I can certainly miss something.

 

[IBallEngineer]

Happy to have you looking in and feel free to comment--there is more than one way to skin a cat and some are better than others. I won't claim I have this circuit fully modeled in my head--I can certainly miss something.

I have my theories, but the first rule of electrical troubleshooting it to check the easy things first. Something I have a hard time with because I want to cut to the chase. But most people don't move that fast, which is fine. The fact that he's getting things on only with conditions leads me to condemn the DRL Relay(main), but it could still be something simpler. I'll follow along and throw peanuts.