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Chevrolet TrailBlazer Electrical Problems



  • All I can say is good luck. I've had my 03 Trailblazer at so many shops I have lost count. Nobody can fix the electrical problems; nobody can tell me why the "service engine" light is on.
  • burdawgburdawg Posts: 1,524
    No it's not true. For the problem you describe I would look for a loose or faulty connector in the wiring harness that connects the passenger side systems to the main harness.
    For the check engine light, the first place to look is always at the fuel cap. Is it on straight? Is it snugged down? Does the rubber seal in the cap have cracks in it like ours did? I wiped a little thick grease on the rubber seal on the cap and put it back on and the check engine light went away in a couple of days. Replaced the cap and no more problems.
  • I am experiencing same problem. My headlights are flickering,dash lights will dim down at same time,also note the gauge to drop below 14 for several seconds. I have replaced the battery and alternator. Any suggestions?
  • I have been noticing my headlights flickering & at the same time dash lights will dim,also notice the gauge will drop will 14 for the duration. This will usually last several seconds. Sometimes it will only occur once or twice and other times it will persist for the entire ride. I tried going to dealer for computer diagnostic,nothing showed up. I have replaced battery & alternator. Any other suggestions?
  • I have the same symptoms on my "05" - it just started this week and I have no idea what it could be? All of us that have these light problems should bring this to the department of transportation - consumers groups - and GM = this is very unsafe and should not be affected by an out-of-warranty situation --- this is UNSAFE and should be a recall to repar no matter what mileage!!
  • I have the same problem with my 05 Trailblazer. It only happens in cool damp temps and I have found that as long as I let the truck warm up for a few minutes it does not do it while driving. I had it to the dealership a couple times but they had no answers as it would not do it for them. I had it to my local mechanic and he thinks it is an issue with the voltage regulator sticking. I agree that is should be a warranty issue.

    I also have trouble with my speedometer not working after a few minutes of driving. Have not gotten too many answers on that one either.

  • bigfigbigfig Posts: 35
    I added windshield fluid and when using the rear wiper there is no fluid coming on the rear glass but inside. How do you remove the rear panel to unclog the hose since fluid is coming out but not on the glass and the wiper is working?
  • When the outside temp goes below 5-10 degrees the battery voltage drops to 6.8-7.2 volts which means absolutely nothing works on the vehicle. 45 days ago I replaced a 2 year old Sears Die Hard Gold series battery (an 8 year battery) with a new one. The problem went away for 45 or so days. Last night the temp went to -2 degrees. This morning, the battery read 7.1 volts. I jumped started it, letting it run for 30 minutes. Now it starts fine. I checked with the Chevy dealer I bought it from and they say it is up to date on all recall notices. They also say they have never heard of this problem. After searching the web I find that hard to believe. Previous posters mentioned corroded computer connections. Where is this computer located?

    In addition to the battery issue, I have another with the front passenger door electrical system. Sometimes all the electrical stuff works fine and other times nothing works, mirror adjustment, switch lights, window, and lock. If any work then they all work. I can drive during the night and watch the lights on the switches turn on and off. It looks like a connector problem but I can't find one that seems to cause the problem.

    Any ideas for either of the problems would be greatly appreciated.
  • burdawgburdawg Posts: 1,524
    During the 45 days the problem went away, did the temperature drop below the 5-10 degree point at any time?
    I think I would do this, but it depends on your personal level of ability:
    The next time low temps are expected overnight, disconnect the battery. If the battery charge stays up then you have a pretty good idea that the battery is OK. If that's the case then I would suspect some system in the vehicle is turning on when the temperature drops down, or some component is being effected by the cold causing a load on the battery. Under these conditions you could verify it by measuring the resistance across the battery cables. It should be quite high. That's going to be very hard to diagnose, since it only occurs during cold weather.
    If after the battery colds soaks overnight the charge is low (assuming the charge was good before the cold soak), then the battery is likely weak. You need to keep something in mind, just because a battery is new or has a good warranty, that doesn't mean the battery won't fail. Batteries today are shipped wet, which means that they start aging the day they are filled with electrolyte. If they sit around on a shelf for a long while, they may be already old when you get them.
  • Thanks for the reply. I had not thought of disconnecting the battery. Unfortunately, sort of, it is not supposed to drop below 10 degrees for the next week, maybe not until next winter.Thanks also for the info on the battery warranties. I just assumed that the statement that battery was good for eight years was truthful. I should have remembered caveat emptor.
  • My 04 TB just developed a stange electrical starting situation.
    The battery does not have the power to start the vehicle, but the battery tests just fine. I was thinking that ti could be the alternator, but now the battery will not hold a charge when I have charged it--the volt meter shows as low as 9 volts after charging
    The interesting twist to all this is---If I just try to start it normally, it won't start--not enough battery power, the gauges go all the way to far left and the clock on the radio resets to 12:00.
    On the other hand, if I quickly just barely turn the the key in the ignition swith to start and release it, somehow the ignition system sems to dig deep for enough battery power to actually get the vehicle started. The gauges all go full left and the clock still resets, but the vehicle starts--something it won't do if I hold the switch in the start position.
    I am baffled after reading some of the posts here but am hopeful someone can shed some light on this problem.
  • mrfryanmrfryan Posts: 2
    I also have an '05 TrailBlazer that just started the same thing. Only when I start it in the morning and when I leave work (After it's been sitting for awhile). The last few days have been damp too. I had the Alternator and the Battery checked and they were both fine. Please let me know if anyone has a solution!!!
  • Just an update. It turns out the problem is not temperature related. I have had the voltage drop overnight a few times when the temp stayed at or above freezing. I have not yet found the problem. One side note to this though... If I put my old Sears battery charger on it for only a couple of minutes I can start the car without problems. When this happens I can watch the in-dash meter go to about 7 volts, hover there for 5 or so seconds then jump right up to its normal position of 14 volts.
  • itagoitago Posts: 1
    I am not sure what the problem is but I took it in for a diagnostic and they told me that the BCA need further diagnostic service. But my main complain is that I had changed the ignition fuse for about 8 times noa and it blows out everytime I drive for more than 20 miles or so. I really need help. I was told by the mechanic that did the original diagnosis to take it to a chevy dealer but I want to know first how much it will cost to fix something like this. :confuse:
  • seah1018seah1018 Posts: 5
    I have a 2006 Chevy Trailblazer EXT LS with 65000 miles on it. The car has recently started acting up electrically, I think. When ever I turn on the air conditioner a set of warning lights comes on and the dash starts beeping. The lights that come on are the emergency brake light, the ABS, the Traction control and the 4 wheel drive train, the air conditioner will not blow except in the back. If I turn the a/c all the way to level 5 the warning lights will not come on but I can not put it any lower than 5. Yesterday I tried just having the rear air on rear control and the same thing happened, the lights came on and the beeping began. This has been happening off and on for a few weeks, never with the rear air control until yesterday. Does anyone have any suggestions? I tried unplugging the battery for 20 min to reset the fuse but the problem persists. Thanks :mad:
  • ajscott19ajscott19 Posts: 6
    I have a 2005 Trailblazer and about 9 months after I bought it I was driving at night and my volt meter dropped causing my dash lights, head lights and tail lights to flash like a strobe light. After it started it seemed that every other day it was doing it and would not stop until I pulled over and re started it. I took it to the dealer I bought it from and they replaced the altenator, a week after it was replaced the same problem occured so I brought it back and they couldn't find anything wrong with it. As soon as I left the dealer it starts doing it again. I decide to take it to another chevy service and they replace the altenator again (I told them that this was already done) A week after I pick it up it starts again so I take it back and they replace the ground fault wire. Again after I pick it up it happens and they tell me they can't duplicate the problem (yeah right) By this time I am so frustrated I write chevy and explain everything in which they set me up an appt. at a chevy dealer which is for tomorrow. We'll see how that goes, but I hate my trailblazer and will never buy one in the future. Has anyone else had this problem that they figured out what was causing it?
  • mrfryanmrfryan Posts: 2
    It sounds like you have the same or similar problem as mine. Mine is the secondary air injection pump for the exhaust. My check engine light came on and it read the code for the secondary air system. I replaced the check valve and all was well for about a month. Then my check engine light came back on and my truck started randomly doing what you explained. The Volts would fluctuate back and forth and in the mean time the lights was dim like a strobe light. It would only do it for about a minute and then it'd stop. Turns out the after I replaced the check valve, the actual electronic pump went bad and was causing a drain on the system. They only want some $400 to replace it!!!!!!!!! The dealership said that it shouldn't affect performance of the car, it's just to disperse the pollutants in the exhaust. So instead of replacing the pump, I just pulled the relay for it and all is well (except my check engine light is always on).

    I love my trailblazer... even with it's little quirk. :blush:

    I hope that helps and you figure out what's wrong with yours!
  • ticadooticadoo Posts: 40
    My 2003 TB EXT just turned 76000 miles. To look at it from the outside and inside, you would think it was a perfect truck! This has to be the strangest-acting vehicle I have ever had...and I am getting to I am afraid to trust it...but I am stuck...I lost my 2nd job and can't afford to replace it.

    Last week I was coming home from 2 hrs away (family member in hospital)..on the interstate...and the windshield wipers came on by themselves...switch was off and it was NOT raining. This has now happened three times.

    This past weekend, I stopped to get gas (another 2 hr trip), turned the engine off..key was out of ignition, I was pumping gas...kept hearing something..the rear A/C was on and blowing! So, in addition to putting over $100.00 worth of gas in my truck last week (16mpg)...I have all these strange things...

    Two weeks ago I had to replace the water pump..$400.00. Now, when I start the truck and get ready to take sounds like a jet plane trying to take off. I have people stop and look at me....I guess it sounds like I am getting ready to "speed" off...but I'm not... :mad: What could this be?
  • ajscott19ajscott19 Posts: 6
    I took it back and the dealer said the truck was supposed to do that...yeah right! They could find nothing wrong with it, who know's I get the feeling that I will never get the issue fixed.
  • It's the dreaded fan clutch!

    Check out all the past threads and you'll find that many of us have had to replace the engine fan clutch. And your right, it sounds like a jet engine.

    Good Luck

  • ticadooticadoo Posts: 40
    I've already replaced that too! :mad:
  • nutrinomannutrinoman Posts: 10
    The others are correct for the "jet plane" sound. I had it and it sounds like a harrier taking off. Your fan clutch has died. I replaced my own. If I remember correctly the clutch was somewhere between $150 and $200. You have to disconnect the transmission coolant lines and then remove the radiator to give you enough room to replace the clutch. With a friend helping it took us about 1.5 hours to replace it.
  • ticadooticadoo Posts: 40
    How long are these supposed to last? I had mine replaced just over a year ago. :mad:
  • jspr363jspr363 Posts: 1
    Hi gang 1st time posting. The key will not turn to off position(where you can remove it) it stays in the aux position keeping dash lights on and running down battery overnight, everything else is ok. It all started when the shifting colum was accidentally moved to park while the car was rolling slowly ahead. The transmission seems to be fine goes into all gears and park no problem. What interlock should I look for that is holding that key from coming all the way home? thanks Jon
  • My oil light stays on for 20-30 seconds after the engine starts (05 TB) my brothers 05 is now doing the same thing - both have about 40,000 miles on them, have had oil changes at 3000 miles - no leaks - oil level is perfect.
    Is any one else having this - or has anyone found the cure?
  • over the past couple of weeks everytime I turn my car on my clock is back at 12:00. Now my car is having trouble turning over. Why???? :o)
  • burdawgburdawg Posts: 1,524
    The battery is probably bad.
  • 05 Trailblazer LS. Headlights dim and AMP meter dives sporatically - most evident at night, of course. Dealer replaced fuse box under hood, but the problem returned a short time later. Dealer then replaced 'faulty' alternator, but the problem returned. I notice the alternator output (AMP meter) falls during hard acceleration, such as when accelerating on highway entrance ramps. When engine RPMs settle after shifting, the problem usually goes away. Faulty serpentine belt or idler pulley? Crappy electrical system? The headlights random dimming at night is a huge distraction.
  • I have been having the same issue, altenator was replaced twice, ground fault wire replaced, now they are telling me they cannot duplicate the problem and Chevy's are made to do that! Yeah right, since when are your headlights, dash lights etc. made to strobe? I've had enough and will never buy a chevy again
  • bigfigbigfig Posts: 35
    I have an '03 Trailblazer and one night my low beam headlights went completely out but did have the high beams and drove home using the high beams. In talking with my local Chev. service dept., they suggested changing the relay switch part #1501-6745 which I did and have not had any problems since. I do not know if this will solve your problem but you may give it a try. The relay is located in the fuse box.
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