2016 ram 2500 draining battery

[Travy199]

Hello new here,
I have a 2016 ram 2500 cummins and im trying to diagnose an electrical problem. The truck has newer batteries but keeps dying every time i go to start it. I have removed an aftermarket front camera and harness, removed a “karr security system” and attached relays that i thought were causing the issue. When i sit inside the truck, locked, the radio starts to buzz and seems like it doesn't fully turn off. I pull the radio fuse and it stops, put the fuse back in and it starts again. Now with the radio plugged in i have unplugged and re plugged in everything that i can find that is attached to the harness and nothing changes. I even tried my buddies good working radio and it has the same problem in my truck but not his so i don't think it’s the head unit itself. Please help i’m at a loss right now. Thanks in advance

 

[hemihustlin]

what codes are you getting?

 

[Travy199]

Im getting no codes/check engine lights. Just dead batteries

 

[Slinge]

Are you sure all aftermarket accessories are removed , along with related wiring ?
Sounds like it to me ...maybe not ?

 

[mtnrider]

Load test the batteries before you go too far down a rabbit hole, you have all the symptoms of a bad cell in a battery

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[Travy199]

Load tested the batteries, one battery was reading 295CCA and the other was reading 7CCA. They were bad. I got new ones on a warranty which was nice and hopefully that fixes my problem

 

[RamDiver]

Load tested the batteries, one battery was reading 295CCA and the other was reading 7CCA. They were bad. I got new ones on a warranty which was nice and hopefully that fixes my problem

How old were these batteries?

I like the Amprobe for testing for parasitic mystery current.
I bought one on sale at Amazon.ca for about $50.
It's one thing to suspect a mystery current, but much easier if you measure the current draw.

Open the hood, lock the truck and leave the FOB in the house. Wait 15 minutes, make sure the EVIC is still off, and start measuring the 12 VDC heavy gauge wires on the batteries for current draw.





Do you own a basic digital multimeter?
At least, you could take frequent measurements after a shutdown and monitor the B+ to be sure your truck doesn't have a parasitic current.


And, welcome to Ram Forum.

.

 

[Jacob Maguire]

I have NO experience with this tool but an interesting way to approach parasitic drains:

This is Game Changer For Parasitic Drains

A dead battery is the symptom — not the diagnosis.In this video, I walk through a real parasitic draw on my Silverado and explain why each test works, what c...

www.youtube.com

 

[RamDiver]

I have NO experience with this tool but an interesting way to approach parasitic drains:

This is Game Changer For Parasitic Drains

A dead battery is the symptom — not the diagnosis.In this video, I walk through a real parasitic draw on my Silverado and explain why each test works, what c...

www.youtube.com

That was the only way back in the '70s & '80s, or the days before the Internet and Amazon, when a DC clamp meter was expensive.
These days, a DC clamp meter can be purchased online for less than $50.





As much as the thermal camera concept is attractive, I'm not convinced of the reliability of finding the culprit these days, when many of the electronics are buried.

The clamp meter will identify the current draw, and fuse pulling will find the circuit, PDQ.
For those who are more patient or have a larger time budget, checking the voltage drop across the fuses isn't too difficult.

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