2006 Chev Trailblazer - Radio Fuses Blown

[Tim Martin]

This is one I'd like to find an answer to. The owner brought in this 06 Trailblazer with a 4.2L engine that we installed a Jasper unit. The engine replacement went well. That is until after we the customer got it and brought it back saying that the radio/clock was not working. We checked, and the fuse #41 was blown. I replaced it with a new fuse which promptly blew. I put another fuse in and instantly the radio started emitting smoke out the cd player. Obviously there is a serious issue. What I am trying to find out is this: Is this radio failure connected anyway with engine replacement? I should mention that when the owner brought it in he initially thought he may have a starter issue. Well, we checked and the battery was only at like 9-10 volts. I am thinking that the low battery voltage may have had something to do with it but I need to somehow be able to convince the owner of that. He is a former mechanic with many years experience and he understands. But I am really puzzled.

[Jeff @ Able Auto]

Tim it looks like a dedicated circut in the power distribution diagrams. I can't see where it would be related to the engine. And if the radio smoked then there is the problem. Just my $2.98.

[steven kiser]

Sounds like two separate issues to me. Possibly there was a CD in the radio playing and the battery was disconnected or something along these lines but it still should have cleared. Bottom line here is the amount of serenity you're willing to loose on this. If it were in my shop I would explain to my customer that after looking into all the circuitry involved there is no reasonable explanation that could be found as to why the radio puked. I would continue before the customer could jump in adding that since it did happen after the engine was installed I would take care of it. An exact match to what was in the vehicle would be installed. We all know these radios can be purchased from salvage yards for under 75 dollars and it would take under 1/2 an hour to install. The customer should be happy that it was dealt with in a timely manner. Another twist on this is I would ask the customer if he was toying with the idea of having another radio installed to better the sound system. If that were true I would allow a 75 dollar payment towards that radio. This is a simple issue that has a simple resolution. Again if it were in my shop there would be little time spent trying to figure out why. I would use the time to show customer that there was no tie in the system that would cause the radio to fail but I would take care of it. This is more of a customer satisfaction issue than anything else. I've seen many shops lose customers over an issue that would cost under a hundred bucks to put it to rest.

[Tim Martin]

I may be in good stead on this one. The customer stopped in this morning to say that he had contacted one of his good friends that works at an area GM dealership and this fellow told him that he has seen this very thing twice in the last few years. It appears that if the radio is turned on when the battery is disconnected then when the battery is reconnected there is a voltage spike in the electronic/digital radio that then blows the fuse. At this point, the radio likely needs replaced. In this case, I do not have an angry customer but rather with this customers prior mechanical experience, he understands that in todays world of all this electronics this kind of stuff may happen. Having said all I did so far, the situation is not resolved but rather getting interesting.

Stay tuned. Because it appears that the moral of the story is that any inside electronics and accessories must be turned off before the battery is disconnected.

[timbre4]

My brother-in-law's daughter was driving one of these Trailblazers and they experienced intermittent electrical oddities. It got sold or traded off!

[Jeff @ Able Auto]

Had a Trailblazer back in August that had a major fuse box melt down. turns out the DRL relay had "stuck" and melted the box. Had to replace the box, engine harness and cut in a body harnes at the firewall.

[Tim Martin]

I have this sneaking suspicion that us older techs, and maybe many of us need to sharpen our awareness of the possibilities when we get to work on these highly electronic controlled vehicles. What I mean is that we will need to take/make precautions to avoid electrical meltdowns in the systems on these vehicles. And, I am also thinking that we will need to document, as much as possible, that we have taken precautions to avoid any future electrical disasters.