electrical issues

electrical is not my forte, with that being said lets get started... First get the code read that is turning the check engine light on... Then check all your battery cables is sounds like you could have a loose one or a bad connection... If none of that sheds light on the situation, I'll need a volt reading across the battery terminals at idle... This will eliminate several possibilities since these can be caused by low system voltage.

With the Trailblazers there quiet a few iussues with the ignition switches, but it sounds like more thn that. You're going to have to take it to your GM dealer to get it diagnosed.

As Rich McClure mention I also recommend having a GM dealer diagnose the problem. However my first guess would be the defect Body Control Module and/or other associated Module would be defective. Even if my guess is correct, it could require an expensive GM Scan Tool to program a new module, which again I agree with Rich's recommended action. Then again does your Trailblazer have OnStar? assuming you have the service, digital equipment upgrade and your Trailblazer has Remote Diagnostic capabilities, just another idea, but could be more money than you anticipate. Otherwise Onstar can observe exactly what is going on with the vehicle and send the information to a nearby GM dealer. Therefore being able to zero in on the problem.

3. the reason why it stalled is maybe because of a bad alternator or alternator belt, so it wouldnt be giving the engine and accesories enough power so it shuts down. 1. the lights are automatic, as soon as they sense darkness they turn on and there is a switch for them to the left of the steering wheel almost beside the door and turning that to the left turns lights off, even when its running and high beams are used through the turn signal stick. so it could be something with an error there. or could just be turned off accidentally

I think the root of the problem is it's a Chevy, they really skimp on build quality for little things.

ha yeah ok. chevy is a bad company. even though they have dozens of models that go until 300k miles or more without issues.

aha ya also chevy has the same truck as gmc envoy, buick rainer, oldsmobile (discontinued) bravada, saab 97-X. so allll of them except the saab are the same. saab is just sweeeeet

Though they are not perfect, they are not as bad as you think they are. 1991 Chevrolet Corsica went 218,000 miles 1992 Chevrolet Lumina Euro has about 160,000 miles my 2000 Chevrolet Malibu LS 184,500 miles and still going

Buick Rainer has also been discontinued as well, way too much model duplicate without distinct differences.

yaaap yet they still make the same ones buick enclave, gmc acadia like make somethin different for once. then now the trailblazer is taken over by the traverse

ok well I have an 06 Chevy Trailblzer LT with heated leather seats and a bunch of electrical issues it would take me all night to say but just a couple of things the drivers door automatic controls dont work cant roll my window down or may not get it back up it and that happens to be where the control for my heated seats are and living in Iowa in mid winter and having leather seats with no heat and the heat in the truck working only half the time in the front is not cool actullaly that makes my leather seats extremley cold it chills me to the bone apparently there was a recall on the door controls and it was fixed once as I bought it used and I said well apparently it didnt work because the same issues are happening again it turns its self on and off when it wants to and I can actually hear it in the door when it does that and I have learned it is a fire hazzard so this scares me and I worry sometime my heat wont turn on and I will freeze to death if this winter doesnt end it is the coldest its been in decades with negative 20-40 below many days and I have to depend on my vehicle to get me to work and back which is 35 miles from my home and I cant depend on it and of course this all got the worst in the winter we know its electrical and my family has always been Chevy people there are some out there that run forever however I have researched the 06 trailblazer of course after I bought it and started having problems and I said and what I reccomend is that from now on when I buy a used or even new vehicle I am not gonna get it right away I am gonna give it a couple of days and do a lot of research on problems and recalls the vehicle has or had this electrical would normaly cost around 1,000.00 but we have the best mechanic and the cheapest and he is a whiz at electrical so it will only cost about half that but you would think GM would do more than just the couple of recalls they have done on it they need to recall the entire electrical system this is all I have to say about this it makes me angry to talk about it and partly because of the used car dealership I bought it from wont help at all

Talk about run-on sentences. That was a doozy. Could these problems have to do with a bad instrument cluster? I just bought a 2003 Trailblazer LT with the straight 6 and 4wd, with the instrument cluster as-is and a warranty on the rest of the truck. But it does weird things, like the dash lights, interior lights, and stereo all lose power when you put it in gear. The 4wd mode selector knob doesn't work so it's stuck in 2wd. And the back seat power windows only work in Park. And of course all the gauges are useless. I'm using an android app for a speedometer but that won't tell me if my engine overheats. It doesn't look that expensive or that difficult to replace the instrument cluster but it would be reassuring to know that's what's causing all my other problems.

Being an owner of a 2002 Trailblazer, I might be able to answer a couple of these questions. I know this is an old thread, but may be useful to someone currently experiencing issues. If your 4WD selector switch does not function and is stuck on 2WD or blinking, most of the time this is due to the TCCM not "waking up" when you start the car. I've had this issue sporadically in my vehicle, though not enough to warrant a fix. Usually after a time or two starting it up, my 4WD switch behaves normally. If your selector switch is not working, you may be able to pull a TCCM from a 2004+ Trailblazer, but you will need it programmed at the dealer to work properly with your 2002-03 vehicle. Stalling at a red light can indicate something as simple as a failing CPS (crankshaft positioning sensor). I had this happen a couple of times after I purchased the vehicle. The CPS costs about $20, and takes about 5 minutes to replace (one bolt, very easy). The OP sounds like they are having electrical issues, but are probably experiencing other problems as well (I wouldn't lay all of these problems as an electrical-only issue). There is plenty of information out there for TBs - check trailvoy as an excellent resource. All in all, the trailblazer is a decent vehicle. The first couple of years (2002, 2003) are notorious for having design flaws that were fixed in the later 2004+ versions. Before spending a ton of money at a mechanic, investigate these issues yourself. Anyone with some time, patience and decent mechanical ability should have no problem performing some of these easier fixes...

Check low beam relay that was my problem

There is a ground point (a ton of stuff grounds here) on the passenger side below the radio/ac section, behind the carpet. Take this apart and clean the connections, maybe shave the paint down to metal, apply dielectric grease and reattach. Do the same thing at the alternator, and any other ground you can find. I’ve actually jumped all the ground studs together all the way back to the battery with some decent grade automotive wire on an old 91 Jeep Cherokee (that no mechanic could fix), and the thing never had a problem again.. Just saying: if things have bad ground, they will look for another path to ground resulting in all kinds of kooky behavior.

07 trailblazer loss of power as u are driving all light go dime how to fixs