Bridged battery terminals with ratchet while leads were attached, now will not start

MICHAEL JOHNSON2

MEMBER
1992 JEEP CHEROKEE
6 CYL
4WD
AUTOMATIC
180,000 MILES

So I was hooking up off road lights and in attaching the clips between the nut and the battery cable my ratchet touched the other terminal. It gave a brief spark and there was a small pop. The battery immediately started losing power, and trying to crank it I could hear the cranks slowing down. I put a different battery in and gave the battery a charge and tried to crank it again, but it sounds like the battery doesn't have enough charge. Did I blow a fuse in the vehicle? Or fry my ECU? I want to know why my Jeep won't start.

3 Replies

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

Yes, we've all done something like this at one time or another. My last one was taking off the strut tower brace that runs along the top of my engine. It has two bolts on the firewall and three on each side of the engine bay on the strut towers, two on top and one on the side. It was the one on the battery side that got me. My battery is situated so that the positive terminal is closest to the strut tower and I forgot to take my extension off the ratchet. so as I loosen the bolt and start whipping the ratchet back and forth I slapped it on the positive battery terminal. Won't do that one again. LOL!
I have included a link for you to go to down below:

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

This guide will show you how to do a load test on your battery. My concern here is that when you arced the battery terminals you might have grounded a cell causing a short in it. Each cell holds 2.1 volts and if one is shorted or dead the battery will act just like you are describing. Go through the guide and get back to us with what you find out please.

Thanks,
Alex
2CarPros

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Wednesday, April 3rd, 2019 AT 1:11 AM

MICHAEL JOHNSON2

MEMBER
2 POSTS

I know a cell in the battery is dead. I hooked my multi meter up to the battery and was watching the voltage drop like a countdown clock. But I borrowed a friend's battery to try to crank it and it still won't start. Battery read +10 volts on the multi meter before I hooked it to the car, and now it seems to have a dead cell as well. I put my friend's battery on a charger and it goes up to a little over 11 volts, but drops almost instantly back down to 10 volts or less, and seems to continue dropping the longer the charger is unhooked. Did o blow a fuse? Or fry my ECU? Why is a different battery draining when connected? Why won't a different battery at least turn it over?

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Wednesday, April 3rd, 2019 AT 1:27 AM

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello again,

This sounds like a major parasitic draw, Can you please check the wires coming off the positive battery terminal and make sure you are not grounding out somewhere. Short of that, I would have to say that your buddies battery must have been real close to failing as well. Get back to us with what you find out please.

Thanks,
Alex
2CarPros

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Thursday, April 4th, 2019 AT 12:17 AM