Volt meter fluctuating

[Andrewcodd24]

hi everyone so I’m having a bit of an issue that is starting to really stump me.
I’ve been daily driving my Jeep for the last week because my car broke down and I’m waiting for it to be fixed anyway on my way home tonight the check gauges light came on and my battery gauge was low probably reading about 10-11 volts. I pulled over and took a look really quick but didn’t see anything out of the ordinary wiggled the terminals even to see if they were loose and everything checked out fine. About another 15 minutes of driving the battery gauge went back up between 13-14 volts and stayed right around that area with a little fluctuation here and there. When I made it home I looked at the positive terminal and saw it was cracked so I change it with a new one and started it up for it to read right around 10-11 again and eventually coming back up to above 14 and fluctuating between 13-14. I rechecked everything and all is right, secured and clean. I just don’t know what to do next. This is a brand new battery I replaced when my starter went bad right around July of this year. Can someone please help me out on this.

 

[TJ Jim]

Put a meter on the battery and see what the actual voltage is reading would be a great place to start

 

[Andrewcodd24]

Put a meter on the battery and see what the actual voltage is reading would be a great place to start

You know I just remembered, last week I filled up with gas and when I went to start it back up it was hardly turning the motor over. But when I turned the key off and tried it again it fired up fine. Is there a possibility I bought a bad battery that is just now showing symptoms?

 

[TJ Jim]

Yes. And hopefully you checked the battery posts. Shiny lead on the post. Shiny lead on the inside of the terminal and tightly snugged down on the post. If you allowed the parts store to install the battery they seem to have missed the training class on correct installation of batteries.
Battery quality ain’t the same as years ago.

 

[Jerry Bransford]

Your symptoms are commonly caused by a bad battery connection. Remove both battery connectors and wire brush both the battery posts and the inside of the connectors until they're bright and shiny clean.

A $5 battery brush makes short work of that job.

 

[hear]

If it's not any of the above... I had some low battery readings once, plus some fluctuations & gauges turning on & off that I couldn't explain. Till I saw that my idler pulley spit the bit. Somehow it was still rotating on the busted bearing and didn't make too horrible of a noise. I drove on it for at least 2.5 hrs, figured if the fan was still turning & keeping the temp down I was good to go.

 

[Andrewcodd24]

If it's not any of the above... I had some low battery readings once, plus some fluctuations & gauges turning on & off that I couldn't explain. Till I saw that my idler pulley spit the bit. Somehow it was still rotating on the busted bearing and didn't make too horrible of a noise. I drove on it for at least 2.5 hrs, figured if the fan was still turning & keeping the temp down I was good to go.

I’m going to try a new battery and get some new terminals tonight and see if that works

 

[Andrewcodd24]

Yes. And hopefully you checked the battery posts. Shiny lead on the post. Shiny lead on the inside of the terminal and tightly snugged down on the post. If you allowed the parts store to install the battery they seem to have missed the training class on correct installation of batteries.
Battery quality ain’t the same as years ago.

Thank you for taking your time to help me out when I get out of work tonight I am going to get a new battery probably a agm type battery and maybe get some new terminals while I’m at it. Thank you for the help I will keep you posted on how it works out

 

[Jerry Bransford]

Avoid Optima batteries, they aren't what they used to be.

 

[Andrewcodd24]

Avoid Optima batteries, they aren't what they used to be.

I changed the battery with a duralast agm battery last night as well as changing the terminals. Still having the same problem. Where should I look now?

 

[Andrewcodd24]

Avoid Optima batteries, they aren't what they used to be.

So after the new battery and the drive to work this morning. I’ve noticed a few things. When I first start my Jeep the voltage gauge will stay right around 10-11 volts until I get out onto the main road and accelerate up to 55 mph then it comes up into the 13’s. Also when I play the radio, if I blast it the voltage gauge will quickly drop down to about 12.6 volts but will slowly make its way back to around 13.6 volts. Could I have a bad voltage regulator?

 

[TJ Jim]

The voltage regulator is in the pcm so hopefully not the regulator. Is your drive belt slipping? Can you take your alternator to the parts store and have it tested? Does it work correctly if your radio/amp is completely turned off? Is your cable between the battery and alternator in good shape? The cable secured and tight connected to the alternator?

 

[TJ Jim]

Post a picture of your engine. Focus on the battery to alternator and a second picture of the fan belt area.

 

[Andrewcodd24]

The voltage regulator is in the pcm so hopefully not the regulator. Is your drive belt slipping? Can you take your alternator to the parts store and have it tested? Does it work correctly if your radio/amp is completely turned off? Is your cable between the battery and alternator in good shape? The cable secured and tight connected to the alternator?

I’m praying it isn’t the voltage regulator. The drive belt I put on about two years ago it’s just starting to pull the lettering off of the outside I changed the idler pulley at the same time as the belt. At the point of connection where the wire is secured to the alternator is a little rusty. And when the radio and subwoofer are off the battery stays right in the range of 13.6 to 13.7 sometimes going up to 13.9 and sometimes dropping down to 12.9. I’m going to clean up the connection to the alternator once I get off of work.

 

[TJ Jim]

Disconnect the battery so you don’t send fire everywhere

 

[hear]

So after the new battery and the drive to work this morning. I’ve noticed a few things. When I first start my Jeep the voltage gauge will stay right around 10-11 volts until I get out onto the main road and accelerate up to 55 mph then it comes up into the 13’s. Also when I play the radio, if I blast it the voltage gauge will quickly drop down to about 12.6 volts but will slowly make its way back to around 13.6 volts. Could I have a bad voltage regulator?

do you have an external amp for your stereo?

 

[TJ Jim]

do you have an external amp for your stereo?

Just reading his post I suspect he’s got one of those thump thump radios and it’s dragging his alternator down. Makes the headlights flicker as he’s going down the road

 

[Andrewcodd24]

So after I got my car back up and going I’ve had time to mess around with it and found the issue. The stud on the alternator that holds the wire that runs to the fuse box was super loose. Turns out it was hanging on by a thread inside the alternator. I’m not quite sure how it cracked the way it did. Could have been from the 50 degree to -4 degree drop we had up here in ny. But I changed the alternator out and she seems to spinning like a top now.