Why is it that sometimes these posts show up and sometimes they don’t. I think I am doing it the same everytime, but sometimes after I hit “POST YOUR REPLY” (sorry about the caps but that is the way it is shown above), enter my response and then hit “submit”, it never shows up again.
The daytime running lights are repaired. There is no DRL module, the only way to turn them off is with park brake application. The circuit does not run through the high beam indicator, but there is a DRL indicator on the dash to remind you when it gets dark that your other lights are not on.
Even though both headlights worked on both high and low beams, one new sealed beam corrected the problem of no daytime running lights.
Apparently there is third element in these Phillips H4666 sealed beam assemblies. One must have shorted to ground and caused both to become innoperative. I only replaced the right one and now both work. Neither worked before.
I have worked in the automotive industry for many years. I realize the value of having the correct information and I realize all that information is available in a service manual. I kind of thought this site would assist people with problems that didn’t have a manual or problems that a manual would not cover. I am sure there are vasts amounts of experience that read and try to answer problems that are posted here.
I appreciate everybody’s assistance and I hope all this information may help somebody else.
2000JIMMY: I’m really glad you got your lights working again! I hope my one statement didn’t sound harsh. By the way, did any of my suggestions help? Anyway, there’re are a lot of Experts here and I hope we all helped you one way or the other.
Hellokit,
This is a moot point but the Haynes Repair manual #38036 does not cover the SUVs, it only covers the 4 vans ('97-'01) Chev Venture, Olds Silhouette, Pontiac Trans Port and Pontiac Montana.
You uncovered some strange electrical circuits. You revealed that your vehicle has sealed beams, as opposed to “composite” headlights. The ARRC site (through my local library web site) has the wiring diagram. After some study of this complex, complicated, circuitry, I’ve discovered a couple of unusual things: When you turn the headlight switch on, power goes to the left headlight (high and low beams). and y’s to the right head light (high and low beams). The power goes through the right head light elements, and through a black ground wire to ground. The left headlight elements ground (dark blue) wire goes through the DRL Relay to a ground wire. When the DRL is energized, power comes through the DRL Relay and down the dark blue wire (which was the ground wire) to the left head light elements. Power goes through the left head light elements to two wires, to the right head light elements, to ground. // So, take out either head light, and turn on the DRL Relay, and neither head light will work. Turn the headlights on, and pull the DRL Relay, and the left headlight won’t light; but, the right headlight will light. // Once you realize that power and ground circuits do this flip-flop, it’s much easier to understand the DRL system.
THE SEALD BEAMS HAVE ONLY THREE TERMINALS, BUT ONE TERMINAL IS TWISTED SO IT IS NOT PERPENDICULAR TO THE OTHERS, LIKE MOST SEALED BEAMS. I WOULD GUESS THIS IS SOME KIND OF SIGNAL THAT THIS IS NOT THE USUAL SEALED BEAM.
YES, KARL, YOUR SUGESTION ABOUT BULBS GOT ME THINKING ABOUT GOING BACK TO THE BASICS. LOOKING FOR THE SIMPLE THINKS ARE OFTEN OVERLOOKED. BEFORE I GOT INTO A WHOLE LOT OF UNNECESSARY WORK, I THOUGHT I WOULD JUST TRY A SIMPLE BULB. EVEN THOUGH BOTH BULBS APPEARED TO BE WORKING, ONE WAS NOT RIGHT. I SOMEHOW LUCKED OUT AND FOUND IT TO BE THE RIGHT SIDE BULB, WHICH WAS THE FIRST (AND ONLY) THAT I REMOVED.
I’m glad it worked. I think you have some idea of why it worked (replacing the right sealed beam headlamp, and because the headlights are in electrical series). You’re right, unlike the Chevy vans, the Chevy Blazer doesn’t have an ambient light sensor; but, it does have a DRL control module (and DRL relay). // We learn something every few days, regardless of how much we strive not to. I know I did.
Several people, along with NYBo, have cars on the idea train. Kudos to them all. A couple of times 2000JIMMY said that …“both low/high beams work properly”…From the wiring diagram, I can’t see where that is possible, and to have the fix to the DRL be: changing the right headlamp… The headlights are just regular high/low sealed-beam lamps. I do see where it’s possible have a low beam out on one lamp, and (even) a high beam out on the other side, and the DRL still light BOTH lamps (though, not as brightly). On the Blazer, one headlamp on, and one headlamp off (in DRL mode) isn’t going to happen. Other makes (maybe, other Chevy models), might have “Popeye” DRL’s.
Honestly, both headlights were working on both low and high beams. I checked them several times. The high beam indicator was also working properly. I checked these things as a result of the answers I had received here.
There is a DRL relay, but I could not find a module. The only repair completed on this vehicle was the replacement of the right side (passenger) sealed beam. The daytime running lights are functioning properly as a result of this repair.
wiring can be tricky the day light driving bulbs that turns on should be the high beams with 6 volts to them they use high beams for day time driving since they are not use as much. look for a bad ground wire to body a simple job. since both go out together.
ALL CAPS may be easier for you to read but most people don’t agree. If they did, then books and newspapers would be written in all caps. Upper and Lower case was invented to make it easier to read.