Lost instrument cluser, no tach and no speed...

Well, my battery for my '03 Trailblazer finally bit the dust and I purchased a new one and replaced it. As luck would have it, I dropped a wrench between the positive terminal and ground - sparks flew. After changing my underwear, I completed the work and started the truck. All seemed good as gold. Not very long afterward though, my instrument cluster, lights, guages, you name it were flickering off and on (mostly off) like my truck was possessed. The truck will start and run, but there is are no inst cluster readings. I'm having a intermittant buzzing sound pulsing through the speakers too. Any ideas? I'm hoping beyond hope I didn't blow the ECM!

Well, my battery for my '03 Trailblazer finally bit the dust and I purchased a new one and replaced it. As luck would have it, I dropped a wrench between the positive terminal and ground - sparks flew. After changing my underwear, I completed the work and started the truck. All seemed good as gold. Not very long afterward though, my instrument cluster, lights, guages, you name it were flickering off and on (mostly off) like my truck was possessed. The truck will start and run, but there is are no inst cluster readings. I'm having a intermittant buzzing sound pulsing through the speakers too. Any ideas? I'm hoping beyond hope I didn't blow the ECM!


OUCH! I saw someone with a wedding ring on, arc a battery when they were installing it, it was an eye-opening experience, to say the least!!

I'd recommend that you take it to the dealership or a trusted high-end mechanic if you have one (One with access to the OBD2 diagnostic tools) and have them go over the entire electrical system. It could be a lot of things other than the ECM, but someone with the right diagnostic tools will be able to tell you what to replace before you start guessing and trying to figure it out. It might cost some $$ to get this diagnosis due to the time involved, but tell them up front that you only want an estimate of what needs to be done (don't let them do any work or replace anything without asking you first) to help keep costs down a bit. Have them also check the output of your alternator to verify that it's working as it should as well. Get it all in writing for future reference.

If you don't do anything, one by one, I imagine parts will start failing on your truck due to the voltage fluctuations that are now present, and that can quickly become costly, or worse, potentially leave you stranded somewhere if a tolerance is breached and some vital engine control is shut down, along with the engine, and you're stuck. Or worse, if a wire got too hot during the arcing incident and some of the insulation is worn off, it could start a car fire or short out another circuit and cause more problems. Electrical problems are time-consuming to diagnose, however, well worth it for the peace of mind that everything is now fixed and will not be a problem in the future.

Better to be safe than sorry with electrical problems. No doubt you've learned your lesson to be very careful with the battery, alebit a little too late. :frown: I wish you luck... Be sure to report back with your results!!

--zepcom

You know what? I'm a dumb a$$. The bolt/nut that secures the brace that rides on top of the battery cover (to help keep the battery in place) - you have to remove it and 2 others to get that brace off. Well it's pretty damn close to the top left fender, and I didn't have the choice tools I wanted at the time. So, when I was trying to undo that particular nut and bolt, sometimes my eyes and hands would drift and I ended up loosening the ground bolt. Suffice it to say the ground wire was loose enough to cause the electrical problems. I didn't realize I had loosened it that much, and I THOUGHT I tightened it up sufficiently enough after I had discovered my faux pas. Well it took the mechanic about a couple of hours to figure out my stupid mistake. So money lost, but truck fixed! A lesson learned.

You know what? I'm a dumb a$$. The bolt/nut that secures the brace that rides on top of the battery cover (to help keep the battery in place) - you have to remove it and 2 others to get that brace off. Well it's pretty damn close to the top left fender, and I didn't have the choice tools I wanted at the time. So, when I was trying to undo that particular nut and bolt, sometimes my eyes and hands would drift and I ended up loosening the ground bolt. Suffice it to say the ground wire was loose enough to cause the electrical problems. I didn't realize I had loosened it that much, and I THOUGHT I tightened it up sufficiently enough after I had discovered my faux pas. Well it took the mechanic about a couple of hours to figure out my stupid mistake. So money lost, but truck fixed! A lesson learned.


Glad to hear it's fixed.

I hear ya about the trouble getting the battery out ... those braces and the plastic cover are a pain in the a$$.

If you don't mind me asking, what did he wind up replacing to 'fix it' and how much did it cost ya?

Anyhow, glad that it seems to have been a minor fix, that's always good!

--zepcom

I think it was about a century mark. I just told myself that was a hundred dollar lesson - expensive, but at least the truck is back to normal now. God I miss those warranty days.