Quad Beam Headlight Problem***SOLVED!!!!!!!!

[F9K9]

Arrgggggghhhhhh! Mine stopped working again but, I attacked it after screwing with my aux back-up lights, that use a relay, for about 3 hours last Sunday. Got the reverse lights going while working with a micro torch to solder with in high winds. Replaced relay double checked everything then replaced the headlamp, grill, grill guard, and front skid which all need to be pulled. Worked fine. Tonight, I can't even describe what they were doing. Should have taken a pic at their reflection in the window at the parts store. When on low beam, one low beam is bright and so is a high beam, all four are working when on low beam. When on high beam, all four are working but, in a different pattern.

Sheesh, I bet I screwed the connections up at the relay. Wait, I'll take a pic.

On low beams only.



High Beams

[roadrunner]

Seeing pics like that just makes me so happy I never messed with mine!

[F9K9]

Seeing pics like that just makes me so happy I never messed with mine!

Oh, go lay down or I will send the flock back in your direction!

[fallvitals]

You Kentucky boys can sure bugger up a sure thing!

[F9K9]

You Kentucky boys can sure bugger up a sure thing!

Yeah, it just takes us a little time (6 years) to do it.

[roadrunner]

I thought the flock was already here judging by the number of items on both of my vehicles needing repair lately. If it's your flock take em back I got enough problems!!

[F9K9]

Well, I've eliminated the mod, cut out the sections of wires that might have been damaged by the scotchloks, soldered them and covered them with heat shrink. I've also pulled the pass side head light and examined all the wires and the thing is still acting nuts.

When the low beams are on, the pass low beam looks normal but, the pass hi beam is glowing. The driver's side low beam is dark with the high beam faintly glowing.

When the high beams are on the the pass high beam looks normal and the pass low beam glows. Both high and low beams just glow on the driver's side.

This is driving me nuts!!!!!!!! Remember, I completely eliminated the mod so there are no connections to check.

[F9K9]

Another update........

I went ahead and reinstalled this mod with another new relay since it wasn't working right stock anyway.

I'm not running DRLs and have the DRL relay's one tab bent up to eliminate it. So, my setup is as follows;

Green w/white to #85
Yellow to #30
#87 to a good ground
purple to #86. All this is irrelevant because it isn't working correctly without without the mod installed but, it did work well for 6 years.

I'm getting about 8-9 volts to the lights with the engine off and 11.7 volts at the battery terminals. Tested every fuse and all are good. I'm thinking a bad ground or BCM. I would check the grounds if, I knew where they were. I know where the tail light grounds are located but that isn't helping me here.

Thoughts anyone???????

Cleaned the already clean battery connections and even bought and installed new side post battery bolts

[rlrnr53]

Reed, check the ground on the headlights, Its possible that you may have a wire that is corroded inside the insulation. You can check for corrosion in the insulation by feeling the wire. If there is corrosion, the insulation will feel kind of lumpy and usuall will feel larger than good wire, other than that the only thing I can think of would be a bad relay.

[F9K9]

Reed, check the ground on the headlights............

That's what I am asking. I am confusing you and myself by throwing into the quad headlight thread. I tried to split the topic but, couldn't quite bring myself to do it for fear of screwing it up.
It's messed up with the wiring in stock configuration with good soldered connections. I was so confident that the problem is on the engine bay side of the radiator support that I buttoned it back up. That's no easy task with the grill, brush guard and front skid involved. I went back and installed the quad mod with a new relay before doing so. I replaced the quad mod relay two times. Usually when the mod fails, you revert back to how the system originally works with either just the 2 low beams or just the 2 high beams working. I've got all four either just glowing or one somewhat normal when on high and low beam.

I have the FSM on CDs but, the diagrams don't show the ground locations, or at least show them where an aging baby boomer can translate them.

[rlrnr53]

The best I can figure, is the ground for the headlights is to to the left of the radiator about a third of the way up from the bottom of the radiator support. Thats from the 01 shop manual. I'm guessing that the other years would be similar. After looking a little more, there are grounds on the right frame rail just ahead of the crossmember.

[HenryJ]

It looks to me like you are now running tri-beam reduced intensity. The highbeams run rotating grounds for reduced intensity day time running lamp operation. Somehow the left headlamp is tied into this as well.

Disconnect the purple wire. It is not used. That was a problem way back when I started the quadbeam mod. The way that you have it attached where a ground wire should be it is being used as the ground and back feeding the others.

Quadbeam mod

Splice tap the green w/white wire (high beam +) attach to relay "activate +"(#85)
Splice tap the yellow wire attach to relay feed (Normally Open #30)
Attach a wire ,or wires, to a good ground and connect it to the relay supply (#87) and to relay "activate - " (#86).

That should fix you up.

[F9K9]

It looks to me like you are now running tri-beam reduced intensity. The highbeams run rotating grounds for reduced intensity day time running lamp operation............

I probably deserve some sort of major scolding but, all that I know is that my set up ran well for several years. I didn't have DRLs because I don't care for them and I do know that you find them good for some very good reasons.

I had completely eliminated the mod during the course of troubleshooting my problem today. All four beams were still burning, in one manner or another, while wired completely stock. Six yrs of you beating upon my hard head allows me to tell you that all the connections were good. Possible scotchloked damaged wires were eliminated with good soldered connections covered with heatshrink. The ground was moved (when dealing with the mod), hit with a drill powered steel brush. All mod contacts are new and even the crimp style connectors were soldered with another new soldering iron. All battery connections were redone and could pass a jarhead drill instructor's inspection and you have personal knowledge of how I keep my engine bay.

I'm willing to remove the mod a second time but, I really believe it is something towards the rear of the radiator support or I wouldn't have buttoned it back up.

BTW, how did the VFD Halloween even go?

[HenryJ]

Can you enable your DRL again? It sounds like it could be part of the equation?

[F9K9]

Can you enable your DRL again? It sounds like it could be part of the equation?

Easily and I had thought of that but, I might have to disable the mod again to make sure it is the problem. I get off an hr earlier now so, I will pull the relay connections, tape them off and see what happens. I should have already tried it but, things weren't adding up to me. It is a source to completely eliminate, though.

[F9K9]

Perhaps I will get to work on it tomorrow. The water pump let go on the heep today and I had just replaced the radiator, hoses and coolant. Had to get it running for a major ride and 4X4 show that is a major fundraiser for children's diabetes this Saturday. The usual things went wrong and it took 5 hrs. Thankfully, I am refinancing and going to add a garage shortly and leave all the troubles of working in cool weather on gravel behind me.

[F9K9]

UPDATE............

Okay, I wanted to follow Brule's thoughts and try to eliminate as many questionable areas that I could. I removed the relay from the equation and taped off all the female connectors. This left me in basically the stock configuration. My OEM DRL relay had a prong bent to defeat the the DRL function. I decided to rule the DRL relay out completely and replaced it with a new stealership's relay that was approx $18. No prong was bent on the new relay and no change was observed.

Just as a reminder, all four headlights burn anywhere from dim to almost normal on low and high beam. They do this with or without the quad beam mod involved. The strongest or brightest beams are ALWAYS on the pass side.

For sheets and giggles, I pulled the new oem DRL relay and the modded relay 2X with the headlights on. The driver's side goes completely out between the swaps or when there is no relay present. The pass side is still on and it has always been the brightest under all conditions.

I'm still thinking a ground somewhere or the BCM. Brule, can you take a glance at the FSM info and possibly tell me where to check grounds? I am just not seeing it there but, you know my limitations.

Once again, all connections are good with the right size heat shrink applied correctly. We have a local electrical legend here and I am almost ready to schedule an appt with him. Might be 2 weeks from now but, he hooked me up with an airbag solution in under 20 minutes when I had chased the light and chime going on and off for months.

[HenryJ]

Have you checked both the left and right headlamp fuses?

Have you checked the high and low beam relays?

[F9K9]

Have you checked both the left and right headlamp fuses?...............

Every fuse has been checked more than once and probably more like 3-4 times.

.........Have you checked the high and low beam relays?

H*ll no, I didn't notice them but, since almost every relay has the same part number except, the DRL one, I should be able to do some swapping now. Thanks for the idea.

[F9K9]

Okay, I know that I am a vehicle newbie but, there are not any rt and left relays under the hood in the PDC. I fell for it and looked and swapped out everything in the PDC that was swappable.

If, I cannot get the locations for the related grounds, I am just gonna suck it up and turn to a guy that has proven to me that he is more than some simpleton with a certificate hidden away somewhere.

[HenryJ]

The grounds rotate. That is how the reduced intensity high beams function. They operate in parallel during normal function and in a series during reduced intensity. That is why it is not as simple as one ground point.

Try pulling the left headlamp fuse and see what you have, then do the same with the right headlamp fuse pulled.
Also document the changes with the highbeam relay pulled, and then the lowbeam relay pulled.

I'll look over the results and the schematics to see if we can narrow down where the problem lies.

[04crewvt]

I have not looked to see if this is the case in our trucks but do we have any fusible links in our headlight harness? If we do maybe one of them has been damaged.

[HenryJ]

I think the fusible links in our trucks are the maxi fuses.

[F9K9]

................Try pulling the left headlamp fuse and see what you have, then do the same with the right headlamp fuse pulled.
Also document the changes with the highbeam relay pulled, and then the lowbeam relay pulled.

I'll look over the results and the schematics to see if we can narrow down where the problem lies.

Thanks Brule but, this is all that I am seeing. There was nothing in the cropped sections appeared remotely related to headlights

[HenryJ]

Looks like you are right about not having a low beam relay. That is the Envoy and diamond editions. My mistake.

So, all lights go out with the relay pulled, right?

Left lights out with the left fuse pulled and right lights out with the right fuse pulled.

Next suspect is the multifunction switch. Does it operate properly?

[F9K9]

Stock

Low Beam

Pass Low beam near normal. The pass high beam and both driver's side bulbs glow dimly

High Beam

Pass high beam near normal, the low beam pass side is near normal but not 100%. Both driver's side bulbs glow dimly.

LT HDLP fuse removed.

Operates same as Stock low beam lights in current state.

RT HDLP fuse removed

No lights but, dash Hi beam indicator on.

DRL relay removed

Low Beam on pass side only
High Beam on pass side only

HDLP PWR relay removed

Zero, zip, nothing, bingo fuel!

This is beginning to resemble a Daimler-Chrysler POS HEEP!!!!!!!!!

[HenryJ]

Ok, all stock and both lights are on the passenger side when the high beams are on. Highbeam indicator illuminated with the relay removed. Does that point to a short in the multifunction switch?

[F9K9]

I just don't know, Brule. You have to remember electricity and I don't play well together. What else can we check before I start throwing parts at a problem. Advance has replacements for $177 and Rock Auto has them for $118.

Looks like some DTCs may be stored. I have a fellow club member with a good scanner. Might try to hit him up to read them for me tonight.

[HenryJ]

Time to pop the column covers off and give that multimeter a work out. We can pull the connector to the multifunction switch and do some testing there. I don't like to throw parts at anything. Better to spend a little time testing first.

[border man]

Dumb suggestion, but have you tried changing out the bulbs for fresh ones? One of the filaments might be bad, not completely burnt out causing a imbalance in the electrical draw? I know our fleet trucks get bounced to hell and sometimes that causes one of the headlights to be way dim..................

[F9K9]

Heading over to friends house now and bulbs aren't a bad idea either. we'll see what dtcs are present

[F9K9]

..........LT HDLP fuse removed.

Operates same as Stock low beam lights in current state.

RT HDLP fuse removed

No lights but, dash Hi beam indicator on...........

Another lesson learned that probably will not be retained by me, anyway!

This was the key that I missed and I had Brother Brule looking deeper than needed. The LT HDLP was showing continuity when checking the fuses. I was shortcutting and only listening for the audible signal to indicate that it was good before hitting another fuse. The left hand (driver's side) fuse showed continuity but, it was basically blown. It was drawing enough from the rt fuse to light up. When the RT side was pulled, the left had nothing to feed off of and all lights died.

There were no DTCs so, next is discovering why the driver's side fuse blew.

Is any of this making any sense?

[roadrunner]

Looks like the waterfowl are still doing things for ya Reed!!!!!!!!

[F9K9]

Looks like the waterfowl are still doing things for ya Reed!!!!!!!!

Yeah, ain't that the truth!

Instead of migrating North to South, they're migrating from Daimler-Chrysler to GM. Really interested in what Brule thinks about this. Personally, I won't be checking fuses by sound again.

[HenryJ]

What happened when you replaced it? Problem solved?

If not then we have to go back up seventeen posts and start again. Now with good fuses.

[F9K9]

What happened when you replaced it? Problem solved?

If not then we have to go back up seventeen posts and start again. Now with good fuses.

OMG, I wrongly assumed that I explained that it was fixed and forgot your relentless requirement for the justly required end results. Maybe, some of our newer members are not aware of your requirements and some others may think it is harsh but, I appreciate it. I have spent to many hours searching threads only to find that nothing was posted to assist others with a similar problem.

Yes it is fixed! I did not reinstall the mod until tonight to verify that my "take" on the mod worked again. The bad fuse was letting about 4 volts get through somehow. We robbed the horn and fog light fuses to make sure it worked last night.

My lesson learned is to not take shortcuts like checking fuses just by the audible tone utilized by most meters. Yes, there are a boat load of fuses under the cover of the engine bay's power distribution center (PDC) but, take the time to either look at the readings for each fuse or pull them for a visual check if, a good meter is not in your tool inventory yet.

There ie still is a reason why the fuse blew and that will need to be sorted out if, another one goes bad. Before would be ideal but, we all have our priorities. It's cause has been drastically narrowed down since we know that something happened after the fuse.

I want to sincerely thank everyone for their thoughts and suggestions. Brule deserves the most praise because he knows my abilities or "lack there of" and was ready to walk me through a wire by wire meter check.

[HenryJ]

Glad you figured it out.

If you get back into the relay some time you REALLY need to delete that purple wire. Without the DRL you may be fine, but with them you have a conflict if the green/white wire is used too.
If it is working for you, then all is well. If the fuse blows again, revisit the quadbeam mod.

[F9K9]

..........If you get back into the relay some time you REALLY need to delete that purple wire........

Trust me, that wire and your thoughts about it are in my head every time I deal with this mod. I ran across the purple wire thread from a link that either you or Jeremy provided. It may have been a link within a link (OMG) but, it works with the DRL delete. I will bookmark it the next time I stumble upon it but, it works well for me.

For some reason the AHL feature seems important to many members. It doesn't bother me and it should be because I ran "blacked out", on the job, for a couple of decades. I am thinking that initially the DRL was a detriment to me because, I was all concerned about the internet myths of the Silver Stars burning out quickly and I did not want mine burning out faster.

The Silver Stars have not failed me once in 6 yrs and that is probably a better track record than most products can claim.

[HenryJ]

I had that worry with the expense of the Toshiba HIR bulbs. I wish I had kept them, but with my luck they would have burned out the day after I transferred them.

[F9K9]

I had that worry with the expense of the Toshiba HIR bulbs. I wish I had kept them, but with my luck they would have burned out the day after I transferred them.

Hey, this is my turf and everyone knows that bad luck is my territory. Go figure out a way you can get an Avalanche to have an extra tank and meet the Thunder II's extended range.

[HenryJ]

Go figure out a way you can get an Avalanche to have an extra tank and meet the Thunder II's extended range.

On the drawing board, my friend A suburban tank under the back would give me 70 gallons of usable fuel. That puts me out there close to 1000 miles easy.

[F9K9]

I had no doubt that it wasn't on the drawing boards. It just takes 6 yrs of following you and knowing what switches to trip to find out something before getting blindsided in a section somewhere like, NOS.