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Buick Rainier, Chevy TrailBlazer, GMC Envoy



  • I got the entire story. You didn't mention there was a problem starting the vehicle. Then you said that the DRL's start automatically. They don't start until you're in gear. Allright, enough on semantics - if the truck has a problem starting, it's probably time for a new battery.

    It's not GM's fault because they didn't program it to wait until the engine is running to turn on whatever lights come on. If they did that, it would merely delay the inevitable (and annoy those of us who like the lights when finding the truck in a parking lot at night)

    I came to this forum seeking advice

    My advice is to get that battery checked out :^)
  • I think the fuzzy logic that went into the DRL on switch is that they figured you would always have your parking brake on when you start your car. I always have the brake on on when the car is parked, even when it's on level ground. Just habit living in California I guess.
  • I had heard that the V8 would be DOD as well, but I really hope it's just an option. I certainly wouldn't want it.
  • Sounds logical ross. We don't use the parking brake here much. Lots of level ground.It's only used on occasion.
    I think when the warranty passes I'll modify the parking brake circuit with a switch to kill the pre-start headlights.

    In short the tech. manager everything is working fine. He agreed that I should use the parking brake to eliminate pre-start drl's. Thanks
  • ficussficuss Posts: 541
    is not a factor in the DRL's coming on while starting. They do not come on until you shift out of park. I have been in the electronics field for 35 yrs. and have never heard of rush current being applied to a resistive load such as a bulb. If that were the case, the bulbs would indeed burn out upon turn on, as you would get much more than 12 volts across the filament for a short time. It may apply to a compressor or other motorized device, but I doubt it applies to light bulbs. I think most halogen bulb failures can be traced to improper handling during installation. The tripletts seemed to have a high failure rate for headlights early on. The complaints about bulbs have died down lately. Perhaps someone told the line worker to wear rubber gloves while installing the bulbs. Either that or the OEM bulbs were defective to start with. I don't recall seeing many "one headlight out" cars lately. Most DRL equipped cars I see have both on.
     also, describing normal battery drain as "parasitic drain" may be confusing to some. All newer cars will have a minute battery current drain when the car is not running. This is by design, the clock and other devices must be kept on. Parasitic drain would imply something other than that which was designed into the car. If you live near the ocean, salt spray may cause a small current to flow between battery terminals. If your car has a parasitic drain on the battery, it should be investigated.
  • cparise1cparise1 Posts: 109
    Never had a negative impact from drl's in any of gm's vehicles. Indianadave, hope you get your .1% problem fixed.

    BTW, I was once told-and maybe ficuss or tblazed can confirm or debunk this as a myth-that setting your parking brake regularly extends the disk brake pistons and keeps them from rusting. Its plenty flat here in SE Wisconsin but I always set the parking brake out of habit and in hopes that I am doing a good thing for the disk brakes.

    Ready to be debunked...
  • The parking brake is mechanical, no hydraulics involved, per factory svc manual. Using it regularly would certainly help prevent the actuator and cables from rusting/corroding/freezing up and no longer working properly.
  • quickdtoo is correct. The parking brake doesn't actuate the rear calipers, as you would expect. The parking brake assembly uses shoes and the inside of the rotor is like a small drum.

  • zeenzeen Posts: 391
    I have only a couple of months left on my 36 month lease. I'm turning it in and will probably buy a smaller SUV that will be easier to fit in my garage and will get better gas mileage. However, the Envoy has been largely trouble free and, as it approaches 34k miles, it has not even the slightest rattle or squeak. I have the SLE. I have heard that the loaded models had a number of problems. I guess the simplicity of the base model was an advantage.
    One humorous anecdote; When we first got the Envoy, there was a rattling sound in the roof near the storage compartment. The dealer tried 3 times to fix it. I took the compartment off and wedged a tennis ball up there and the rattle stopped. The ball has been in the roof now for almost 3 years and maybe someday, someone repairing or salvaging the vehicle will discover it and wonder.
  • aldan93aldan93 Posts: 202
    I live in the southtowns of Buffalo, you are correct about having more snow than Buffalo they didn't get wacked this year, But I got you beat, you know its bad when you snowblowing a path in your back yard so your dog can take a dump!!! I have 2 feet in the backyard and four foot drifts in my front yard, Yesterday and Today, scratch today are the only days I have been out of A4WD, I post a pic with my TB tomorrow or so, were getting wacked again with snow!!!! It rained today about 2" poured!!!! now the ground is frozen with snow sticking again!!!! If anyone has any questions about TB's in snow just ask!!! Its by far the best vehicle I have ever owned!!! PAST TRUCKS--> Ford Exploder, Dodge Dakota
  • I just got my 2002 Trailblazer EXT back after the Service Mgr. at my dealership, and the GM Tech that was supposedly flown in, decided that the rattle must be coming from the engine and rather than waste time replacing it piece by piece, they replaced it with a brand new engine. The rattle is still there! 2 weeks ago I was told that my trailblazer is the only one having the problem. Now I'm told by GM customer assistance that it is a common problem with 2002 trailblazers and they will not fix it! They offered me a 75K mile warranty on the new engine only (which was obviously not the problem)and they will no longer look for what is causing the rattle. Anyone have any ideas as to what I can do now?
  • tblazedtblazed Posts: 945
    ficuss states: "I have been in the electronics field for 35 yrs. and have never heard of rush current being applied to a resistive load such as a bulb."

    Quoted from "" (among many other sources, GE lighting, Osram-Sylvania,etc): "Inrush current (initial current through the filament) has an adverse effect on life expectancy. Cold resistance will have a more detrimental effect than hot resistance to inrush current. Life expectancy of incandescent lamps can be maximized by reducing occurrences of cold resistance to inrush current." Like I said... and the main reason why I don't like all the unnecessary automatic on-off business with the headlights.


    above graph from Osram-Sylvania

    "Describing normal battery drain as "parasitic drain" may be confusing to some"

    That's how GM describes the normal drain in their technical papers, like Techlink and in the service manual. That is the accepted term.
  • tblazedtblazed Posts: 945
    Only problem doing that is, then the BRAKE light will stay on all the time and the chime will be going to remind you the brake is still on.
  • lancerfixerlancerfixer Posts: 1,308
    ...please help me settle a bet with a coworker. Does the rear defroster on the Envoy also have elements on the rear side glass, or is that merely an embedded antenna? Thanks.
  • Interesting topic near and dear to me - in the recent cold snap I have also noticed my '03 TB straining to crank and did not think of the headlamps as a contributing factor.

    I had problems with parasitic drain related to the ignition switch. They first replaced my ignition switch to fix a problem with the Service 4WD light coming on and disabling my 4WD. It was an elusive problem that would clear itself if I turned the ignition off then on again. I happened to be traveling and near a Chevy dealer when it happened again. While the light was on, they hooked up a diagnostic tool and commented there was no power getting to the 'rear grid'. A few days after they replaced my ignition switch, I started noticing the dash lights (gear indicators like P-R-D, etc) stayed illuminated even after the car was off and the key removed. I went on vacation for 10 days and came back to a TB dead as a doornail. So dead we had to push it out of the garage and jump it for 20 mins before it would even click when I turned the key.

    They replaced the ignition switch a second time, told me the first one was installed incorrectly (done at another dealer). The look in their eyes told me I don't want to know what they really found inside my dashboard.

    Meanwhile, I am wondering if the severe battery discharge incident caused damage to my battery and my less-than-robust cranking on these cold days as opposed to DRL load.

    Your thoughts and opinions appreciated -
  • It's really bad to completely drain a car battery.
    That will take some life off of it.

    How cold has it been?
    If it's around 20 or so, I don't notice any difference in cranking. When it's 10 or less, the slow cranking is noticeable, but that is to be expected.
  • tblazedtblazed Posts: 945
    Car batteries don't like being deeply discharged. So, yes, you probably have a weakened battery. You might tell the dealer that it just doesn't start like it did, or that it hesitates to crank sometimes, and get 'em to give you a new battery. It's in warranty. Does yours have the built-in hydrometer "eye"? It should appear green if the state of charge is normal, in that cell anyway.

    BTW did a search for "ignition switch" got two pages of old messages about various problems and switch replacements, so don't feel alone!
  • The Rear Window defogger is only in the Rear lift-up glass. It is powered by the two coiled wires connected to the rear glass.

    There is no defogging capability on the side glass. You may see the On-star antenna, or other glass etchings.

    This would apply for the 2002-2004 TB, Envoy, Bravada, as well as the earlier body styles 1995-2001, since I have both styles.
  • tblazedtblazed Posts: 945
    "Does the rear defroster on the Envoy also have elements on the rear side glass"?

    '02 Envoys had an optional diversity antenna system, with antenna elements on the L & R rear side quarter windows. That's probably what you see. Also, there's no vertical mast antenna if it has the diversity antenna system. I think they did away with that option on the '03s.
  • ficussficuss Posts: 541
     One result of a goolge search for tungsten halogen bulb rush current

    "Most of us have played around with halogen bulbs and found out that the only thing that really decreases life is over voltage and high G-forces."

    tblazed, why would anyone describe a normal condition "normal drain" as a "parasitic drain". The two are not the same. As far as rush current is concerned, if the bulbs are designed to withstand the .004 second rush of higher current the first time they are turned on, they should last for the average expected life of the bulb. The .004 second of higher current is factored into the life expectancy rating. I have never seen a warning label on a bulb "caution, turning this bulb on will shorten its life expectancy". Every part in our cars will break sooner or later. Sooner if you use them , later if you don't. I once heard that the life expectancy of the average car driven an average of 50 mph. was only 2000 hours. I could not believe it until I did the math, 50 m/h x 2000 h = 100,000 miles. Most cars don't reach 100,000 miles.
     BTW, are tungsten filament bulbs and Hologen bulbs considered the same for your graph?
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