HID questions

[Blckshdw]

You don't have to undo the harness any more than you already have. The fender ground is fine, there should be grounds on the plugs that go into the ballast. (the black wire...) Most relay harnesses I've seen have a length of black wire, and then a ring terminal on the end for a total of 3. One for each ballast, and one for the relay. If you've got a pair of free floating ground ring terminals that aren't connected, that explains your issue with the relay turning on/off, but no juice at the ballasts.

 

[IAFF78]

I just took the harness out figuring that it was the problem. I attached a pic(hopefully) so you can see which kind it is. The top two wires are the plugs which get hooked to the ballast and the HID bulb wire. The 3rd on down is the ground and the bottom one is the power wire.

Now when i went to hook the HIDs up I got nothing. Story of my life. Time to recheck everything again.

 

[Blckshdw]

I'll be honest, I've never seen a relay harness quite like that one. The power source wire looks like it has 2 wires on it? The outputs to the ballasts look like they also have input sockets for them too?

 

[IAFF78]

Is there another relay harness that i can purchase from somewhere else? I will call DDM and talk to someone and see whats going on.

I am stumped as to why my HIDs dont work now after i hooked them back up how i originally had them. I check fuses and saw that the 10a fuse for the left lowbeam was burned out. So i took the 10a from the highbeam and substituted it and still nothing. I dont even have the side marker lights either.

Im beyond pissed. Any suggestions?

Thanks,
Kevin

I'll be honest, I've never seen a relay harness quite like that one. The power source wire looks like it has 2 wires on it? The outputs to the ballasts look like they also have input sockets for them too?

The wires from the harness leading to the HIDs have 2 plugs. One that goes into the ballast and the other from my guesstimate goes into the matching plug coming from the HID wires.

This is how i wired it. The factory OEM plug from the old bulb goes into supplied plug. The HID bulb has wires that go through a grommet and attach to the plugs leading from the ballast(2 thick wires with 2 small seperate plugs). The othe plug from the grommet plugs into the other wire harness plug. If you go to DDM's website and go to the download section, you can find pics of how its supposed to work.

 

[Blckshdw]

Here's a pic from an Ebay relay harness. These are the kind I've always seen, more or less.

#1 gets hooked up to the battery
#2/#3 get hooked up to a convenient grounding point on either side of the engine bay
#4/#5 plug into the HID ballasts
#6 accepts the OEM low beam plug on the driver's side to activate the relay.

 

[IAFF78]

Still no HIDs. I put everything back the way it was and nada. FML

 

[Blckshdw]

Still no HIDs. I put everything back the way it was and nada. FML

After replacing your fuses (3,6, 46), can you get your stock light bulbs to come on?

 

[IAFF78]

After replacing your fuses (3,6, 46), can you get your stock light bulbs to come on?

I blew fuse 6 so i replaced in for now with the highbeam fuse. fuse 3 is ok. I switched 45 and 46 and still nothing. So i just put the good fuse from 6 back into the highbeam and im gonna have to run with them for tonight(not my favorite option). I am totally stumped. This HID mod has turned into a complete nightmare.

Any help would be appreciated.

Thanks,
Kevin

 

[Blckshdw]

I blew fuse 6 so i replaced in for now with the highbeam fuse. fuse 3 is ok. I switched 45 and 46 and still nothing. So i just put the good fuse from 6 back into the highbeam and im gonna have to run with them for tonight(not my favorite option). I am totally stumped. This HID mod has turned into a complete nightmare.

Any help would be appreciated.

Thanks,
Kevin

Use your meter to test the fuse sockets for the low beam relay/fuses, make sure power is flowing through them when activated. If those are working, then test the low beam plug with the meter.

 

[IAFF78]

I'll have to give that a check later. I hope my tester that i have will do the job.

When i test the fuse socket, do both sides need to test hot or just one? When i test the relay socket, which terminal or terminals need to test hot?

Now lets say that the socket or sockets dont give me a reading, what would be the cause and fix for that?

Thanks,
Kevin

 

[IAFF78]

If you are hearing the relay click, when the low beams are supposed to come on, then your power/ground connections are fine. Focus your troubleshooting on the connections going into your ballasts. If you flipped the plugs going into the ballast around, and there was no change, you need to test the relay harness output connectors to make sure they have 12V. The ballast should buzz for a few seconds as they ignite and warm up, then quiet down. You get that volt meter yet? The bulb connectors only plug in one way, so you can't mess those up.

Pulling power from a stud on the front fuse block isn't usually recommended. Which stud did you use? If you have someone touch the relay harness lead to the battery terminal does it work? You may want to get an extended battery bolt, so you can hook up your harness directly to the battery as intended.

I have the one in the middle. I found it in a box of my old stereo equipment for my old TB. It was still in the packaging. Its been a long time and i cant seem to remember how to connect the factory power wires to the new post. I cant seem to unscrew the oem bolt from the red cover that the wires lead in to. I vaguely remember having to cut the power wires and crimp on a new O ring terminal.

 

[Blckshdw]

I have the one in the middle. I found it in a box of my old stereo equipment for my old TB. It was still in the packaging. Its been a long time and i cant seem to remember how to connect the factory power wires to the new post. I cant seem to unscrew the oem bolt from the red cover that the wires lead in to. I vaguely remember having to cut the power wires and crimp on a new O ring terminal.

Yeah, I'm using the middle style too, the longer one was too long to seat properly in the battery and gave me connection issues. The OEM bolt doesn't unscrew from the rubber casing (so you don't lose it when disconnecting the cables from the battery, I assume) IIRC you have to bend the rubber a bit to expose the edge of the bolt, and pop it out.

 

[IAFF78]

Fuses 3,6 and relay 46 did not get any reading on the tester. So no power is flowing to those spots. What would be the next thing to check?

 

[Blckshdw]

Fuses 3,6 and relay 46 did not get any reading on the tester. So no power is flowing to those spots. What would be the next thing to check?

Looking at the wiring schematic from the trusty service manual, the pink/white wire coming from the BCM (pin A5) runs up to relay 46 (Pin 5) in the front block to trigger the low beams coming on. So if you are not getting voltage at Pin 5 for the relay up front when the lights should be on, then check the pink/white wire at the BCM to make sure there's voltage there.

Also, be careful about posting about your issue in multiple threads. Folks elsewhere might not see your troubleshooting history that's posted here.

 

[IAFF78]

Looking at the wiring schematic from the trusty service manual, the pink/white wire coming from the BCM (pin A5) runs up to relay 46 (Pin 5) in the front block to trigger the low beams coming on. So if you are not getting voltage at Pin 5 for the relay up front when the lights should be on, then check the pink/white wire at the BCM to make sure there's voltage there.

Also, be careful about posting about your issue in multiple threads. Folks elsewhere might not see your troubleshooting history that's posted here.

The BCM is the rear fuse box correct? If so, i did do the DRL killer and i remember cutting and soldering the 2 ends of a pink/white wire to my relay. I'll have to check and see if thats the same wire. If so i'll test the end coming from the harness and the end going into the plug.

 

[Blckshdw]

Yes on both counts, where you did the DRL killer is where you should check next.

 

[IAFF78]

Yes on both counts, where you did the DRL killer is where you should check next.

Ok, i stripped the heat shrink off the wires. A5(pink/white) is what i used for the DRL killer. The wire was cut, stripped and both ends were soldered to sepereate wires that ran to the relay. I tested the wire that runs into the grey plug and got nothing. I then tested the wire that comes in from the truck and still nothing. Even though i soldered them together with electical solder i should show voltage if i had power running through the wire correct? The solder shouldnt impede my test?

Would the next step be to check the rotary headlight switch on the dash? If so how do i test it?

Thanks for all your help btw.

 

[IAFF78]

I noticed that when i turned the headlight switch all the way to the right, i did have the green light come one. Next, i removed the cluster panel and pulled the 2 plugs from the headlight switch. Theres 2 plugs, a 12 wire and 4 wire. I tested for 12 volts and here is what i found.

4 wire plug:
Car on
orange=12v
tan=nothing
brown=12v
green=12v

Same findings for when car is off

Now the 12 wire plug. I couldnt find any numbers for the pins. When i tested the pins i did it from the back where the wires lead into the plug. Couldnt test the front of the plug cause the hole was too small.

Heres how i had it drawn out.
Top row working left to right with car on= 12/no/12/12/no/no with car off= 12/12/12/12/no/no
Bottom row working left to right with car on=12/12/12/no/12/12/ with car off=12/12/12/no/no/12

Hope this isnt too confusing.

Thanks,
Kevin

 

[IAFF78]

Just trying to get my ducks in a line here. If i need a new headlight switch what year TB's will work in my 04? Is there any other model vehicle that has the same switch that would work in mine(ex. envoy, chevy/gmc trucks, bravada...etc)? I ask because around here we have a few decent junkyards with a large selection. I rather hunt one down and grab a used one before i pay 100 bucks for a new one.

Thanks,
Kevin

 

[The_Roadie]

Also, be careful about posting about your issue in multiple threads. Folks elsewhere might not see your troubleshooting history that's posted here.

Totally agreed. I get easily annoyed at that as well. Heck, I usually stay out of threads that appear to focus on HIDs, even if they stray back to being about normal headlight wiring like this one. I saw a post by the OP today on TRAILVOY and connected it to one in a totally different thread and started responding in that thread here. Sigh.....

 

[IAFF78]

I apologize for the multiple postings on different threads and sites. Just tyring to resolve this issue asap before i head back to work. I value everyones opinion and thank you for the help so far. I rather resolve this issue myself before i give a dealership $$$$ to fix it. Hope i didnt offend anyone. I'll start a thread dedicated to my problem so as not to mislead anyone with HID questions.


Thanks,
Kevin

 

[IAFF78]

After having a fit with my HID's i took them out and put the oem HL bulbs back in. Now they dont work. The only thing that I have done to the truck thats still hooked up is the DRL killer.

Heres what i've done so far...

-Tested fuses 3 and 6 and found no voltage coming into them
-Switched relays 45 and 46 and still nothing. Tested the terminal where the relay plugs into and no voltage
-Went to the rear BCM and tested pin A5. That wire was cut and soldered to 2 different wires for the DRL killer. Tested both ends of the wire and no power.
-Tested the plugs that go into the headlight switch. 2 plugs, one has 4 wires the other has 12 wires. The plug with 12 wires has 12v running to some of the pins. The plug with 3 wires has 12v running to 3 out of 4 pins.


What would be my next step? Any suggestions.

Thanks,
Kevin

 

[Me007gold]

Sounds like you messed up something when you did your DRL Killer. But it back to stock and see if you still have the problem.

 

[IAFF78]

Sounds like you messed up something when you did your DRL Killer. But it back to stock and see if you still have the problem.

I forgot to mention but my hid's worked after I did the drl killer.

 

[The_Roadie]

-Tested fuses 3 and 6 and found no voltage coming into them

Not surprising if the relay isn't working

-Switched relays 45 and 46 and still nothing. Tested the terminal where the relay plugs into and no voltage

WHICH relay? WHICH terminals? The relay you want to be checking is 46, and pin 2 should have CONSTANT battery voltage even if the key is off. Where is the other end of your meter when you're doing this? Pin 6 should be a good ground.

Here is the pinout for the fan relay 45. Relay 46 is the same except rotated 180 degrees.

View attachment 18014

-Went to the rear BCM and tested pin A5. That wire was cut and soldered to 2 different wires for the DRL killer. Tested both ends of the wire and no power.

That's bad. When the low beams are supposed to be on, that pin should have voltage.

-Tested the plugs that go into the headlight switch. 2 plugs, one has 4 wires the other has 12 wires. The plug with 12 wires has 12v running to some of the pins. The plug with 3 wires has 12v running to 3 out of 4 pins.

Don't worry about the switch so much yet. Remind me again if you have a "headlight on" lamp on the switch when you turn it to force the headlights on. That will check the function of the BCM and a lot of the control wiring.

 

[Boricua SS]

it sounds like you have done everything except mess with the DRL Killer... i would put everything back to stock, including the DRL Killer, and go from there...

 

[Blckshdw]

Your best bet, if you haven't done so already, is to go to the service manual thread I linked earlier. Download the PDFs for your 2004, one of them is specifically for wiring. It tells you what color wire/pin assignment leads between what devices. That will help you focus your troubleshooting more to where it needs to be, rather than shotgunning in a general area and hoping to find something that stands out.

As for the headlight switches, any of the GMT360 (and possibly 370/305) switches should work. I believe there was a slight change in 2003 or 2004, where the switch gained another position on the dial. Only reason I'm not 100% sure if the LWB switches will work, is because I took mine apart for the LED mod thread, and noticed the circuit board was stamped GMT370...

Edit: This is your thread, so no need to start another one. Also, if you happen to know of any forum members in your area, you might be able to do a simple part swap to test it out before spending any money on a switch.

 

[IAFF78]

Not surprising if the relay isn't workingWHICH relay? WHICH terminals? The relay you want to be checking is 46, and pin 2 should have CONSTANT battery voltage even if the key is off. Where is the other end of your meter when you're doing this? Pin 6 should be a good ground.

Here is the pinout for the fan relay 45. Relay 46 is the same except rotated 180 degrees.

View attachment 2927
That's bad. When the low beams are supposed to be on, that pin should have voltage. Don't worry about the switch so much yet. Remind me again if you have a "headlight on" lamp on the switch when you turn it to force the headlights on. That will check the function of the BCM and a lot of the control wiring.

On my headlight switch there are 4 settings to select from. IF you turn the knob all the way to the left it turns your headlights on. I still have the little green light and amber light come on when the trucks turned on. So i know that the headlight switch is getting power, i just dont know if its sending it back out.

When i tested relay 46, i grounded my tester to the bolt on the Dr side fender. Its a solid ground. I tested the pin you told me too and no voltage registered. I even turned the truck on and tested all 4 pins and none had any voltage. I did the same test to 45 and i had voltage register. So why i'm not getting power to the fuse box is beyond me.

 

[IAFF78]

it sounds like you have done everything except mess with the DRL Killer... i would put everything back to stock, including the DRL Killer, and go from there...

I thought about that but i tested the pink/white wire that leads from the harness and it showed no voltage. So i'm not even getting power to the rear BCM. Thats why i'm hesitant about unhooking the DRL killer just yet. If i have to I will as a last resort.

 

[IAFF78]

Your best bet, if you haven't done so already, is to go to the service manual thread I linked earlier. Download the PDFs for your 2004, one of them is specifically for wiring. It tells you what color wire/pin assignment leads between what devices. That will help you focus your troubleshooting more to where it needs to be, rather than shotgunning in a general area and hoping to find something that stands out.

As for the headlight switches, any of the GMT360 (and possibly 370/305) switches should work. I believe there was a slight change in 2003 or 2004, where the switch gained another position on the dial. Only reason I'm not 100% sure if the LWB switches will work, is because I took mine apart for the LED mod thread, and noticed the circuit board was stamped GMT370...

Edit: This is your thread, so no need to start another one. Also, if you happen to know of any forum members in your area, you might be able to do a simple part swap to test it out before spending any money on a switch.

Me looking at that wiring guide is like us reading chinese. I would be sooo lost and prolly F things up even worse.

Wish i knew someone in my area off here. That would eliminate one problem if i could hook up my headlight switch and see if it works or not. I'm just stumped as to why this isnt working. Heres what ive found so far during my tests.
1.no 12v at OEM bulb plug
2.no 12v to fuses 3 and 6 and relay 46
3.i do have 12v at the headlight switch plugs(that just stumps me) The foglights still work and the dimmer works.
4.no 12v to pin A5
5.flashers still work
6. highbeams still work.

What else should i test? I'm clueless.

Thanks,
Kevin

 

[The_Roadie]

I thought about that but i tested the pink/white wire that leads from the harness and it showed no voltage. So i'm not even getting power to the rear BCM. Thats why i'm hesitant about unhooking the DRL killer just yet. If i have to I will as a last resort.

A lack of power at the pink/white wire does not imply a lack of power to the BCM. It could be a fried BCM, or the BCM thinks the headlights should be off due to a bad input command form the switch. Does the red wire at the large threaded stud on the rear fuse block have 12V?

On my headlight switch there are 4 settings to select from. IF you turn the knob all the way to the left it turns your headlights on.

No, it should force them off. The headlight symbol two clicks clockwise is ON. The counterclockwise position turns the DRLs off using the BCM.

I still have the little green light and amber light come on when the trucks turned on. So i know that the headlight switch is getting power, i just dont know if its sending it back out.

A fundamental misconception you have is that headlight power goes THROUGH the headlight switch like on many older vehicles. It doesn't. The switch sends low power control signals to the BCM, and it's the BCM that controls the relay. That way, the BCM can accept OTHER signals, such as from the remote entry system, and flash the headlights as a confirmation of using the key fog. If you've set it up that way.

When i tested relay 46, i grounded my tester to the bolt on the Dr side fender. Its a solid ground. I tested the pin you told me too and no voltage registered. I even turned the truck on and tested all 4 pins and none had any voltage. I did the same test to 45 and i had voltage register. So why i'm not getting power to the fuse box is beyond me.

Could be a very simple flaky relay socket. How exactly did you poke a wire into the relay socket to test it? Pin 2 MUST have 12V because it's on a battery bus, and not even going through the ignition switch. Your fuse box may have internal corrosion or a loose socket if you poked anything into it that's spreading the socket sides apart.

Do your fog lamps work? Brake lights?

 

[The_Roadie]

...This is your thread, so no need to start another one. ...

I've merged the two main ones into this one now. Everybody stay put.

Me looking at that wiring guide is like us reading chinese.

That's why you find experienced volunteers like us here. The OS has hardly anybody who can read schematics anymore. We live and breathe this stuff.

 

[Blckshdw]

Me looking at that wiring guide is like us reading chinese. I would be sooo lost and prolly F things up even worse.

That's why you find experienced volunteers like us here. The OS has hardly anybody who can read schematics anymore. We live and breathe this stuff.

Over the last few days, you've spent quite a bit of time getting familiar with the contents of your front and rear fuse blocks, the BCM, and the headlamp switch. You've got a decent understanding of what does what, so I'm willing to bet if you looked at a schematic of the headlamp system, it would make a lot more sense to your not-yet-trained eye than you think. (more like poorly structured English, rather than Chinese )

Give it a try, the worst thing that can happen, is you need some guidance following the wiring layout. And of course we'll help you and get you up to speed. Then you'll be helping other noobs in no time.

 

[IAFF78]

A lack of power at the pink/white wire does not imply a lack of power to the BCM. It could be a fried BCM, or the BCM thinks the headlights should be off due to a bad input command form the switch. Does the red wire at the large threaded stud on the rear fuse block have 12V?

No, it should force them off. The headlight symbol two clicks clockwise is ON. The counterclockwise position turns the DRLs off using the BCM. A fundamental misconception you have is that headlight power goes THROUGH the headlight switch like on many older vehicles. It doesn't. The switch sends low power control signals to the BCM, and it's the BCM that controls the relay. That way, the BCM can accept OTHER signals, such as from the remote entry system, and flash the headlights as a confirmation of using the key fog. If you've set it up that way. Could be a very simple flaky relay socket. How exactly did you poke a wire into the relay socket to test it? Pin 2 MUST have 12V because it's on a battery bus, and not even going through the ignition switch. Your fuse box may have internal corrosion or a loose socket if you poked anything into it that's spreading the socket sides apart.

Do your fog lamps work? Brake lights?

Yes, the red wire going to the rear fuse box has power

My typing error. I meant to say if you turn the headlight knob all the way to the right it forces the headlights on

To test the relay i used this trick. [video=youtube;C8t25GjZ6i4]http://www.youtube.com/watch?v=C8t25GjZ6i4[/video]
I made this up and tested the 45 socket and it showed 12v. I then did the test on socket 46 and had nada.

Fogs work perfectly
Front turn signals work fine
All rear lights work including the 3rd brake light.

 

[The_Roadie]

I then did the test on socket 46 and had nada.

Yikes, that guy looks a LOT like me.

View attachment 18017

You have a bad socket in the fuse block.

 

[IAFF78]

Yikes, that guy looks a LOT like me.

View attachment 2930

You have a bad socket in the fuse block.

God that's sounds like its gonna be expensive. Where do I get the part? Auto part store?

 

[The_Roadie]

God that's sounds like its gonna be expensive. Where do I get the part? Auto part store?

That's a dealer-only or junkyard part. But take it to an automotive electrician first to take it apart and look for corrosion or loose socket blades. It's not a broken part that you can see most likely. You have to get somebody with some experienced eyeballs in there.

I see your thread on the OS is being met with DOZENS of skilled replies, eh?

It's like crickets chirping.

Headlight help - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

 

[IAFF78]

That's a dealer-only or junkyard part. But take it to an automotive electrician first to take it apart and look for corrosion or loose socket blades. It's not a broken part that you can see most likely. You have to get somebody with some experienced eyeballs in there.

I see your thread on the OS is being met with DOZENS of skilled replies, eh?

It's like crickets chirping.

Headlight help - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

Sometimes the sun shines on the back of a dogs a$$ somedays. I thought i would give the OS another try and it turned out to be an epic fail. :banghead:

For my own curiousity, how did you determine that was the problem? What leads you to that conclusion? With the info i provided you, what made you say bad socket? Just would like to know incase im the person giving the answers someday.

Thanks,
Kevin

 

[The_Roadie]

With the info i provided you, what made you say bad socket?

You said there was no power on relay socket 46, pin 2. The schematic shows that being connected in the fuse block to the "B+" bus, which is a term for permanent battery connected power. No switches, no fuses, just a direct connection to the battery. It must always have power.

View attachment 18018

 

[IAFF78]

Sounds like its gonna be a costly repair. I wish I was good at reading those schematics