19 volts to battery

Jake kozlowski

Jake kozlowski

TJ Enthusiast
Joined
Feb 17, 2018
Messages
314
Location
Elmendorf Air Force Base, Anchorage, AK, USA
2000 Jeep Tj 2.5L

-Brand new X2 battery from batteries plus
-Brand new big 7 wiring kit
-refurb alternator from oreilys 7 months ago

Was doing some tests on all my electrical since i had an asd issue and noticed my battery was dead 2 mornings in a row. It was time for a new battery anyways since my prior one was 10 years old.

New battery unhooked 12.6 Volts (multimeter on pos/neg battery posts)
New battery installed with new cables 12.6 volts (multimeter on pos/neg battery posts)
While running sits at 14.7V for a brief moment then climps up to 19+V (multimeter on pos/neg battery posts)

Battery guage on dash reads 13ishV
aftermarket battery guage wired to cig lighter 13V

SO i was playing around with the multimeter and was testing to see if my grounds were good.
-Neg on battery, positive to firewall bolt where ground is attached no resistance
-Neg on battery, positive to grounding bolt on engine block, 2 or .2 not sure on the setting

What do i need to test next? Is there any other sensors i need to check? No CEL either.

Thanks in advance!
 
How does the regulator only allow 19v on the battery but not to the cigarette lighter or instrument cluster? What kind of DMM are you using?
 
Digital Multi Meter. I just find it odd you are charging at 19v at the battery, but everything inside your jeep is running off 13. I can't come up with how this is possible. What voltage are you measuring at the fuse box under the hood? Behind the glove box?
 
Use the Dmm and check voltage at the fuses behind the glovebox and under the hood.

If the battery is reading 19v, then everything should be reading 19v.
 
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So.... New findings...

Battery was dead when I attempted to start. So I have a draw somewhere.

Once started after jump pack I went to the battery with my multimeter. 12.6 then went to 13.3

After about 10 mins idling I checked again.

On the battery terminals, 12.7 volts.

On the alternator 12.7 volts.

I also noticed the cable from alternator to battery was pretty warm.

Fuses under hood and behind glove box matched, 12.7volts
 
The only thing that could cause 19 volts is the alternator/voltage regulator. Guarantee there’s a problem with one of those.
 
Sounds like the op changed all his power and ground cables. Im really thinking something isn't hooked up correctly with that.
 
Checked all connections, and found the draw on the system.

With jeep off and with multimeter set to 10a I checked all the fuses.

Was reading 1.9-4.1 draw.

The O2 sens 10a fuse, when pulled dropped it to .02 draw.

Started jeep without fuse battery and alternator sat at 13.0 volts idle
 
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