Lost all electrical

The most logical place to look is at the battery. double check the connections, pos and neg. remove the cables and check for corrosion. also, double check the charge on the battery. to lose all electrical it pretty much has to be at the battery or the under hood electrical box. see if you have power there.

Loose/dirty connection at the battery can cause that. Be sure all is clean and tight. If good, go to main power center under-hood and verify power is making there. If it's okay get back to me and we will go from there.

Battery was checked and it is good, however there is a slight discharge when you touch the positive terminal with your hand. A bad battery would not cause the key to refuse to come out of the ignition though, would it?

Unless the tumbler or something in the column is broken, possibly the ignition switch. Do you have power in the truck?

battery is okay, but there is no power to anything else.
Checked all the fuses and relays I could reach. I did pick up on a real faint (weak) clicking under the dash where I cannot get to. Someone asked if the factory installed security system could have malfunctioned.

Is there any power to the under-hood fuse/relay center? need to start at the battery and work towards the interior. The alarm wouldn't let it run/start, not power down the entre truck.

I had to give up and let the pros take their turn. Right now, they are running tests and tracing wiring.
Thanks for all your help.

The Pros are stymied also. Short of pulling the dash off, every possible fuse, relay and module has been tested and retested. They put another battery in just to see and it started reluctantly, however after sitting for two hours the vehicle shut off again. Would I be wrong to suppose that it is not a 'device' problem at all since it would start, but it would be a wiring problem causing a draw in the system that could be 'over ridden' by extra juice.

I wish I knew the answer. I drove all year, accidentally jumped the wrong way, now it won't start at all, no power pass the battery?

Hi Tommy,

Just to be clear, you drove all year with the battery hooked up backwards. Or you drove the vehicle all year and then had to jump start it and accidentally hooked it up backwards just to jump it?

More than likely it is the latter because it is not possible to drive it with the battery backwards (at least I am not aware of a vehicle that can do that).

The best thing to do is start a new post of your own, that way we can get all your specific vehicle info and issues.

https://www.2carpros.com/questions/new

Let us know and we can go from there.

Thanks

True, I accidentally jumped it the wrong way. Loved my trailblazer, now I want divorce..

Checking every fuse, I can tomorrow, then go from there. thanks

Haha. Yeah. I get that. If you jumped it backwards then that would be the place to start which is a blown fuse.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If there are no blown fuses, then we need to trace the power and find out how far we are getting past the battery. What year Trailblazer do you have?

2004 LT, I had just put an entry lock rod clip on, and my battery been draining for a year, jump backed it in reverse OMG, I'm so upset.

Okay. Thanks for that. So, this means we need to start with checking the power from the battery, through the fusible link to the alternator and starter.

If we have no voltage here or not 12 volts, then we may have a battery issue. So, at that point, check the batter to find out if this is shorted.

https://www.2carpros.com/articles/car-battery-load-test

If not, then we need to start moving through the system to find where the issue is.

Basically, the common things that these effects are circuit boards so that means we need to check fuse panels for power and then each module.

Also, we can check for codes and that will help us figure out what may not be operating.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Thanks

Brand new battery was the fix, $175.00.

Thank goodness. Those issues can either be simple like that or really expensive to replace modules. So glad yours is back up and running.

Thanks for using 2CarPros. Please come back in the future.

Thanks for your help.