Complete electrical failure after a new battery was installed backwards?

2008 DODGE CHARGER
80,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC
Avatar
HA45
  • MEMBER
  • 4 POSTS
The car listed above's engine is a Hemi. A new battery was installed backwards, possibly 10-15 seconds before being disconnected and corrected. Smoke seen from hood briefly. Unable to locate the source. Battery ground cable in trunk very hot, some smoke. Started car, it ran and drove but no blinkers, no front door windows, no radio, no door locks. No warning lights on dash. No blown fuses. Drove home and parked. 2 days later the car was used again for errands with the same issues. After leaving the last stop, the speedometer quit working. While returning home the car shut down completely. It would not start again. No lights, gauges, or sounds when ignition switch was turned on.

Tried jumper cables and three things happened:

First: sparks at battery when attaching cables indicating a "short"
Second: the car started and ran
Third: Shut off immediately when disconnected from jumper cables.

Disconnected the car's cables in the trunk from the battery.
Towed car home, battery voltage was 11.9 and it was placed on charger. continuity test on positive and negative cables in trunk failed. Continuity test from pos cable to car body panel bolt failed.
Jul 10, 2022 at 10:20 PM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
Yep, this happens when the cables are reversed it takes out the car's TIPM which are weak to begin with. We can confirm if you can do a CAN. You can get a CAN scanner from Amazon for about $30.00. here is a video to show you how. I have included the TIPM replacement instructions in the diagrams below, it is easy to replace it because the unit self initializes.

https://youtu.be/u-4syLc-ifQ


Check out the diagrams (below). Please let us know what happens.
Jul 11, 2022 at 6:31 PM
Avatar
HA45
  • MEMBER
  • 4 POSTS
I am ordering a CAN scanner. The new battery re-charged to 13.6v.
I connected the positive cable to the battery and with the negative cable still disconnected, checked the current from cable to negative battery post. Read 1.83 and the probe wire got extremely hot in 3 seconds. Disconnected the positive terminal again.
Jul 12, 2022 at 7:45 PM
Advertisement
Avatar
HA45
  • MEMBER
  • 4 POSTS
I'm concerned.
With that amount of power draw, is it safe to reconnect the battery when I get the scanner?
Jul 12, 2022 at 7:51 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
No, I would not reconnect the battery until the TIPM is replaced, something is shorted causing the heat, you might want to try disconnecting the TIPM and do the test again to see what happens.
Jul 13, 2022 at 12:10 PM
Avatar
HA45
  • MEMBER
  • 4 POSTS
I will do that. Thank you.
I'm going to be out of town for 3-4 weeks starting Sunday. So, there won't be much progress to report until I get back. But I will absolutely continue with updates when I return.
Jul 13, 2022 at 1:01 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
Thank you.
Jul 14, 2022 at 10:06 AM