My battery seemed to be getting weak?

HBTJR

MEMBER
2003 CHEVROLET TRAILBLAZER
4.2L
6 CYL
2WD
AUTOMATIC
169,000 MILES

I have a bad draw on my battery. I was doing some testing before I noticed this problem because for some reason the fuel pump relay does not have power when the key is activated. So, I unhooked the battery. I noticed upon reconnecting the battery my battery had 13.0 volts. I turned the key to the on position a few times and my battery seemed to be getting weak so I checked the voltage again and I had 5.6 volts I never tried to crank the vehicle I only turned the key to the on position so now I noticed when I hook up the battery my blower motor A/C will come on just from hooking the cables up. I'm wondering if this is common are is that probably where my problem lays?

Saturday, June 10th, 2023 AT 12:17 AM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
50,492 POSTS

It sounds like the battery is bad but to be sure i would try charging the battery and then use this guide to load test it.

https://www.2carpros.com/articles/how-to-charge-your-car-battery

and

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

Here is how to change the battery out in case you need it. If the battery is okay, I would replace the blower resistor which when it goes bad causes the blower to be on all the time which drains the battery down. Here is the location for that as well which is by the blower motor. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

Images (Click to make bigger)