Intermittant Headlight failure

ApproachMedium · Post by **ApproachMedium** » Thu Jun 24, 2010 9:51 am

Ok so the headlights have done this to me 2 times before two days ago when it happend again. I would go to start it at night and all the parking lights, fog lights etc work. The high beams work but the low beams wouldnt. Next day they will work find again. The other night it did it again. Numerious times I have checked all fuses, relays etc and I cant seem to figure it out. Lastnight when I got home after driving from my friends i started to fiddle more. What puzzled me the most is the high beams working but not the lows? I started hitting the high beam switch a few times quickly cycling it and the lights started working. I guess its my switch? Previously when this happend I recall opening the hood, and after slamming it shut they came on... Could it be in my wire harness? I assume the high beam switch is easy to change so I am going to do that first and see where that takes me.

Just curious if anyone else has experienced this on their CC, Blazer or pickup.

Post by **HenryJ** » Thu Jun 24, 2010 10:14 am

There have been multifunction switch failures. Be prepared that switch w/cruise control (my cost) is $118.29

roadrunner · Post by **roadrunner** » Thu Jun 24, 2010 11:43 am

Don't forget to check the cable connections at the battery. They've caused more than a few intermittent problems.

ApproachMedium · Post by **ApproachMedium** » Thu Jun 24, 2010 4:13 pm

HenryJ wrote:There have been multifunction switch failures. Be prepared that switch w/air conditioning (my cost) is $118.29

Can you clarify this for me? Not sure what the high beam switch has to do whit the air conditioning?

I will check the battery connections. Not sure why that would cause just the low beam to stop working but the high beam and everything else does but anything is possible!

Post by **HenryJ** » Thu Jun 24, 2010 7:19 pm

Sorry

Working on too many problems in between. That should have been cruise control. I'll fix that.

ApproachMedium · Post by **ApproachMedium** » Thu Jun 24, 2010 7:46 pm

No problem! Is the headlight switch inside of the stalk? I know on all of my older GM trucks they were attached to the column and you could change it easily without much surgery. I hope its a simple swap or its getting attacked with contact cleaner this weekend...

ApproachMedium · Post by **ApproachMedium** » Tue Jun 29, 2010 9:24 pm

OK so after a trip to Napa they said the part is a mutli-function switch as mentioned. They will sell me the part new for $291. If I go on ebay I can buy it "new" for $139. Is it really worth the difference in price? The ebay part claims to be new and I guess is just an aftermarket part. How difficult is this to change? Could I try to remove the old one and rebuild it myself? I am pretty good with electronics so that wouldn't be an issue as long as theres no physical parts inside that are broken.

Post by **HenryJ** » Wed Jun 30, 2010 5:02 am

Rebuilding is probably not going to be an option.

I can not guess if the NAPA part will be any better than the Ebay part. I have had a "good" NAPA multifunction switch from NAPA die. They are buying cheap parts to stay competitive.
If you are looking for the "best" an OEM Delco might be that?

I'd be very tempted to give the ebay part a shot.

ApproachMedium · Post by **ApproachMedium** » Wed Jun 30, 2010 10:47 am

Thanks. I figured the Napa stuff is probably not much different then ebay. Ill make a stop over at the local chevy dealer and see what the factory delco part goes for and go from there.

Post by **HenryJ** » Wed Jun 30, 2010 11:34 am

Check Rockauto.com online pricing too. There is a discount code in the classifieds that will just about save enough to cover shipping.

border man · Post by **border man** » Wed Jun 30, 2010 12:53 pm

Rockauto lists the part for $119

ApproachMedium · Post by **ApproachMedium** » Wed Jun 30, 2010 2:23 pm

Nice. Just took a ride to my local chevy dealer they want $235 for the part new. Im amazed they are beating napa on a price! I think ill be going with rock auto as long as with shipping its still less than $139 on ebay. Ebay has free shipping.

ApproachMedium · Post by **ApproachMedium** » Sun Jul 04, 2010 8:15 pm

So I got the part for $99 on rock auto. It arrived yesterday, and funny up untill tonight since the part was ordered the headlights have been working just fine! Well now that the switch is here I am looking for some insight on how to replace it. One of the guys I work with said I need to remove my air bag and steering wheel to get to it. Is this true? Any insight that can be shared on this I would appreciate.

Post by **HenryJ** » Sun Jul 04, 2010 8:27 pm

It has been a long time, but remove the column shroud and take a look. I think it attaches to the side and over the top. One screw is facing the wheel and a little tricky to get out, but I think it can be done without removing the wheel. Do disable the airbag to be safe.

I could be totally wrong as I have been doing way too may of those on the fullsize lately.

ApproachMedium · Post by **ApproachMedium** » Sun Jul 04, 2010 8:39 pm

Thanks Ill take a look at it tomorrow after work.

So how do I disable the bags? Just remove the fuses for my SRS system or can I unplug the bag somehow from under the dash? I have a tool I can reset the SRS lights should they come on.

Post by **HenryJ** » Sun Jul 04, 2010 8:42 pm

I pull the fuse or the battery cables. Wait a while for capacitors in the system to discharge. Even then treat it like a loaded gun.

ApproachMedium · Post by **ApproachMedium** » Mon Jul 05, 2010 9:19 am

Gotcha. Thanks again for all the info.

ApproachMedium · Post by **ApproachMedium** » Mon Jul 05, 2010 12:00 pm

OK I successfully installed the switch without removing the wheel or airbag. It was actually alot easier to replace the switch itself than it was to re-route all the wires. To do this job you need to take the all of the dash panels on the drivers side off, including the one around the gauges so that you can access one of the green and black wired plugs thats connected to the ignition switch. To get to the screw that looks like you need to take the wheel off you need to turn the wheel so the top of it is where this screw is, you can then get in there with the right torx and get it out.

Wasn't bad overall, took me an hour and a half to do, most of which was figuring out how it all comes apart and devising a way to get the wheel facing screw out. Only thing that really pissed me off with this whole situation. The low beams STILL don't work.... They haven't since last night but I haven't checked the fuses since then. Is it possible this is related to the headlight switch itself? Could it be a problem with my BCM or something?

On the plus side I now have a nice shiny new wiper stalk with a cruise control switch that might not turn off if I breathe on it.

F9K9 · Post by **F9K9** » Tue Jul 06, 2010 5:41 pm

It really sounds like something simple that requires you to pull all of your hair out before tripping over the answer. I would start looking and connections and grounds being corroded due to your climate.

ApproachMedium · Post by **ApproachMedium** » Tue Jul 06, 2010 5:50 pm

Yesterday after taking my whole grille apart and testing all the outputs of the light sockets I came across some interesting info elsewhere online about the possibility of the relay being bad, or having a bad ground. With the lights being non operational my left headlight contacts had +12v coming out of both contacts. The other headlight had +12 and the ground seemed poor and didn't give any readings, or hardly any continuity when tested with the meter. After doing all that I didn't feel like ripping my whole air cleaner and fuse box out to see where the ground for the front lights ended up so I just buttoned it all back up and moved onto the relays. After taking the relay in and out a few times I noticed there was one next to it for rear defogs, which I swapped it with, and viola! they worked! I put the original relay back, and they still worked...... It doesn't seem like its the relay itself but probably the ground for the relay.

Also note... Whether the lights are working or not I get 12V to the fuses for each headlamp ONLY if the relay is IN. If its out, they are zero. Explain that too?

Post by **HenryJ** » Tue Jul 06, 2010 8:46 pm

No way will I jump into this one! The whole "rotating ground - parallel circuit - reduced intensity - day time running lights - stuff" still has my head spinning from the quadbeam mod.

F9K9 · Post by **F9K9** » Wed Jul 07, 2010 3:16 am

ApproachMedium · Post by **ApproachMedium** » Wed Jul 07, 2010 9:18 am

LOL oh my. I dont have any reduced intensity issues. Its either it works or it doesnt. Im not looking to make anything happen here beyond my low beams working like they should heh.

Post by **HenryJ** » Wed Jul 07, 2010 9:40 am

Oh, it is all mixed up in there! The whole thing gets pretty complicated. The deeper you look the worse it gets. My condolences.

The low beam circuit should be easier to deal with but you still have the AHL mixed up in it too.

ApproachMedium · Post by **ApproachMedium** » Wed Jul 07, 2010 9:42 am

Yea thats why I stayed out of that thread. Id be happy if everything was jsut working as intended right now

ApproachMedium · Post by **ApproachMedium** » Thu Jul 22, 2010 6:22 pm

UPDATE!!!!

So last week a friend and I, the friend being a certified mechanic in previous career, took apart the whole front of the truck grille, lights wires everything. We cleaned out the two grounds we found behind the headlights that were coming from the headlight wire harness. After doing this we still had zero success with getting the low beams to return on. In fact since then the low beams have not worked period.

Until tonight!
I took a piece of wire, on the passenger side where I was getting no continuity on the ground (test of the ground to the battery for continuity) Attached it to the ground wire and then touched it to the battery negative. After doing that the low beams worked!! the piece of wire was cleaned up, attached to the metal of the radiator support and viola! problem solved!

Now the only side effect from this is when I turn the high beams on the lows stay on. I really could care less as this doesnt bother me.... I believe that shows my problem must have been related to the ground in the relay. Oh well it works now!

Post by **HenryJ** » Thu Jul 22, 2010 6:41 pm

I suspect that you may find that your lows are also on with your DRL now too?

ApproachMedium · Post by **ApproachMedium** » Thu Jul 22, 2010 6:45 pm

humm.... Havent checked that yet because its too dark out now and the light sensor keeps turning the lights on. If i do the auto light override the DRLs are off as well so no way to find out till tomorrow AM when i leave for work... I guess Ill report back!

I hope they arent on all the time...

Post by **HenryJ** » Thu Jul 22, 2010 6:50 pm

I ran with mine on for quite a while

I didn't know that they were on all the time. No way to check unless you park in front of a mirror, or have a friend check for you. They go off in park or with the emergency brake set.
That is what happens when you ground the yellow wire instead of adding a relay like I finally figured out for the Quadbeam mod.

ApproachMedium · Post by **ApproachMedium** » Thu Jul 22, 2010 6:59 pm

Ahhhhhh!!!! Well thats what I did, ground the little yellow wire to the chassis... Ill find out in the morning I can usually see the reflection off my garage door or the back of my fathers pickup if I'm parked in the street. Ill report back tomorrow then I may be needing to figure out relay wiring. grrr!!!

Horsehammerr · Post by **Horsehammerr** » Fri Jul 23, 2010 3:30 am

If you are parked where your truck won't roll away on you, put it in neutral with parking brake OFF and you can walk around to see your four headlights on. Remember to press your Dome Override button, left end of dash, until you hear the chime, and your lights are off. usually takes four pushes of the button for mine to chime but sometimes six

. Anyway, with the right bulbs the four light deal makes the road a lot easier to see at night.

ApproachMedium · Post by **ApproachMedium** » Fri Jul 23, 2010 10:29 am

Sure enough pulled up behind a car at a light on my way to work today and the low beams are on with the DRLs. Im not too concerned except that my $30 philips fancy white bulbs may not last as long. Whats involved with a relay etc to kill the low beam when the DRL is on? I guess I could always remove the relay or whatever for the DRL and just not have DRLs since I find them useless.

Post by **HenryJ** » Fri Jul 23, 2010 10:46 am

Check the right headlamp wiring. AHL relay and fuse as well as the DRL relay and fuse.
Be sure to check the fuses with an Ohm meter. There was a batch of import fuses running around that looked good, but were bad.

Horsehammerr · Post by **Horsehammerr** » Sat Jul 24, 2010 3:57 am

ApproachMedium wrote:Sure enough pulled up behind a car at a light on my way to work today and the low beams are on with the DRLs. Im not too concerned except that my $30 philips fancy white bulbs may not last as long. Whats involved with a relay etc to kill the low beam when the DRL is on? I guess I could always remove the relay or whatever for the DRL and just not have DRLs since I find them useless.

Just push the Dome Overide button till it chimes. This turns your DRL's OFF. They reset automatically the next time you start up but, pushing the button thats already there is a lot easier tha maybe getting a lot of fuses and resisters right. I mean the button works for sure.

ApproachMedium · Post by **ApproachMedium** » Sat Jul 24, 2010 8:35 am

Yea thats what I been doing for now.... eventually ill figure it out though. It would be nice to have things working as intended without the ground modification but oh well! I cant complain now because I can SEE at night again!

ApproachMedium · Post by **ApproachMedium** » Thu Nov 24, 2011 11:20 am

So now after being bored at work and reading the Quadbeam thread, I must resurrect this issue for a moment and ask some questions. Now after reading all about how the DRLs use flopping positive and negative between headlight and DRL mode to run the DRLs at reduced lighting, this better explains my issue that I have with the DRLs keeping the low beams on with them. I like having my high beams and low beams on at the same time when I flip the high beams on, fantastic! But is there a way I can fix my low beams to keep them functional but disable them when the DRL is on?

Just a recap of things, replaced multifuction switch, did not fix. Replaced headlight switch, also did not fix. Checked all relays and fuses to no avail. Swapped relays and even bought new ones, still no fix. In order to get the low beams to function correctly again I had to take the "negative" wire off my pass side head light and ground to the rad support. This provides the path to ground to keep the low beams on when the high beams are, and also activates them with the DRLs. I am curious if I put the relay in for the quad beam mod, if that would make matters worse since the low beams dont work without the wire that I grounded or could it provide the function I am looking for of the high and lows together on high, but not on the DRL mode.

I would love to make this super simple and just totally disable my DRLs but here in NJ now that safety inspection has been eliminated the cops are allowed to write the tickets for anything safety related that they see has been disabled, bypassed, not functioning/unsafe etc.

F9K9 · Post by **F9K9** » Thu Nov 24, 2011 9:33 pm

Maybe completely unrelated but, my lights were acting completely crazy about this time last year. I run with disabled DRLs and the quad mod. I redid the entire mod and soldered all connections. Still the same thing when finished. Some of the four lights were dim and one was out. I checked all my fuses using the audio setting on my meter. Got a good buzz from all fuses. I gave up and let a fellow off road club member look at my situation. He pulled the related fuses and one was blown. Somehow there was enough left of the connection to signal good but, not enough to allow the required amperage through.

I have also had relays that would operate the horn but, when switched to the starter or fuel pump position, they would fail to work.

ApproachMedium · Post by **ApproachMedium** » Thu Nov 24, 2011 11:21 pm

Interesting. I switched the fuel pump, starter, horn, and headlight fuses around like a bad game of hide the ball in the cup and remember which one it was in. I tried swapping the headlight relay with every possible one including replacing it with a new one, still didn't work. I will have to pull the fuses and do a visual check, though I dont believe thats the issue since there is only a left and right side fuse and no fuse for just the low beam which is my point of failure.

I mostly drive it at night for now since we have gone into winter so I shouldnt have to worry about the DRLs till the summer again.

I read you disabled your DRLs by bending a pin on the DRL relay? Why did you do this and not just remove the relay? If you remove the relay does it stop the function of something else on the vehicle?

F9K9 · Post by **F9K9** » Fri Nov 25, 2011 5:07 pm

ApproachMedium wrote:...........I read you disabled your DRLs by bending a pin on the DRL relay? Why did you do this and not just remove the relay? If you remove the relay does it stop the function of something else on the vehicle?

I honestly don't know if, pulling the relay does the same thing, I doubt it or else I would have done it.

I do recall trying to ground on the passenger side and I had issues. Everything should be done on the driver's side with a relay. Brule kept his DRLs and everything was done on the driver's side.

ApproachMedium · Post by **ApproachMedium** » Sat Nov 24, 2012 11:44 pm

So now that my truck has gone thru the first phase of its overhaul one of the items I replaced was the headlight harness which was brittle and falling apart in many places. When I was taking it out one of the ground lines I found was broken, there are 3 that are grounded on the rad support from the harness. Since I have replaced with a new harness the lights have been working however the intermittent problem comes back now and then still. Now, however I can fix it instantly by dropping my fist on the relay and fuse center. I tried swapping one of the headlight relays with the horn relay and it still does it. After reading the service manual more I found theres 3 relays involved with the headlights. Next step is going to be replace ALL of the relays in the fuse and relay center. I really hope its not the relay center that is bad. I checked to make sure the connections on the bottom were all installed properly and tight. It def seems like a relay because once I get the lights to stay on they never just shut back off again. If it was something like a loose wire or connection I would imagine it would be turning on and off while driving. It seems like once I jolt the relays to pick up it stays on for the rest of the drive.

Just some info to add to the site in case someone comes across the forum looking at the same problem. I will be sure to report what I find when I have time to investigate the relays more.