2017 Ram 3500 Tradesman 6.4L V8 battery keeps draining

[carlos22]

This started as an inquiry into whether my battery was dying due to the trailer 7 pin being attached. We'll I've disconnected everything and have been sitting here for a while. I've also made sure my inverter was off. However after maybe 5 min, the dash goes out and then a few min later it comes on again. I made sure the wheel for the dash lights is all the way off and my key is out. I tried to start my truck again and it was struggling as if the battery voltage was low. Also when I pulled codes, the only one there was for low battery voltage. If anyone has had this issue before let me know. This is a 2017 Ram 3500 Tradesman 6.4L V8

 

[2003F350]

Is it the original battery? If it is, put a new one in. You've gotten 7 years out of it, it wants to retire.

If it's not the original battery, check voltage, if it's under 12.2 that battery is for sure on its way out and continuing to use it is putting a LOT of stress on your charging system and could possibly take out other components.

 

[carlos22]

Is it the original battery? If it is, put a new one in. You've gotten 7 years out of it, it wants to retire.

If it's not the original battery, check voltage, if it's under 12.2 that battery is for sure on its way out and continuing to use it is putting a LOT of stress on your charging system and could possibly take out other components.

That was my first thought so I went and swapped out the battery for a new one. I also went to an auto zone and tested the starter, and alternator. Both are good.

 

[2003F350]

In that case it sounds like (and from reading your codes) you've got communication errors, meaning you've got a wiring harness that has issues. It's likely creating a short that is draining the battery.

 

[Slinge]

Did you fully charge your battery before install ?

 

[carlos22]

In that case it sounds like (and from reading your codes) you've got communication errors, meaning you've got a wiring harness that has issues. It's likely creating a short that is draining the battery.

I'm going to check if there's any messed up wires later. This is how it's started today, do I have a weak starter? I feel like that's what it sounds like.
This is how it sounds starting up

 

[carlos22]

Did you fully charge your battery before install ?

Yea and I put in that battery 3 weeks ago. It didnt give me any problems until these last couple days. I've also had my trailer plugged in for the last couple months with no issues until now. I get the feeling that it's my starter, it kinda sounds weak. However, the auto zone machine didn't detect a problem with it.
This is how it sounds starting up

 

[crazy jerry]

is it after market inverter thats hard wired in ? why didnt you unplug the trailer first thing and see what happened ? diagnosis 101

 

[carlos22]

is it after market inverter thats hard wired in ? why didnt you unplug the trailer first thing and see what happened ? diagnosis 101

I don't know if it's an aftermarket inverter. I just got this truck a few months ago. As for the trailer, I've been disconnecting these past couple days when I park. I didn't before because I had never had this issue before. I've had the trailer connected for months without issue.

 

[2003F350]

If it is only draining the battery when the trailer is connected, then you've got a draw going on in the camper. You'll need to start diagnosing the trailer. If it's got fuses start pulling them until the power draw stops. If it doesn't you'll need to look at all wiring.

 

[GPx0]

Put an amp meter between the positive battery terminal and the cable to measure the current draw.
Then start removing fuses until you see a sizable drop. That will narrow down what circuit has the problem.
In older cars this was pretty simple because nothing drew power when it was off. With new car/trucks there may be a number of things drawing small amounts of power, so don't assume the first time you see a current drop you've found the right circuit. One of them should be more than the others. and 'normal' draws should be very low (much less than an amp). If a circuit is draining your battery overnight it should be more than 1 amp.

 

[carlos22]

I charged my battery on Thursday night and checked it this morning. I didn't turn on my truck at all yesterday because i took a day off for a doctors app. This morning there was no change in the battery voltage. I have my OBD bluetooth scanner that i put plugged in, I'm reading the voltage and even with my headlights on the battery is at a constant 14.2~14.3 while running. I have a simple amp meter that might explode if I hook it up to the battery. I have one of those sticks with the mini light bulb and I checked my fuses. They're all good, and I went to check the battery fuse, the top plate was grimy and dirty. I scraped off some of the grime and check for power. After the grime was off I found the plate and nut had power. Now my battery is voltage isn't dropping anymore and I'm getting 12.9~13 V before starting it. I'm confused, scraping some grime off the battery fuse is the only thing I've done, is that a thing for these trucks?

 

[2003F350]

I won't say that yes, that was the issue, but it's entirely possible that the dirt and grime was creating enough of a path for electricity to travel that was causing a power drain. That's part of why cleaning and maintenance are necessary.

 

[Marshall]

14.2 volts shows that your alt. is good, tells you nothing about current draw when turned off.
Regarding current draw, you don't check it when anything is turned on, most meter will handle 10 amp.
You let the truck sit with everything turned off for a couple hours at least to let the computors go to sleep.
best way is use a jumper on the battery post and battery, and meter hooked up the same way.
then unhook the jumper cable or just pull the b+ cable off the battery with the meter on amps.
it should read about 40ma . trailer unhooked of course, everything shut off. don't open doors and leave the key fob in the house.

If you have a battery in the trailer, that could be killing the truck battery, or fridge, electric brakes, etc.

 

[62Blazer]

In regards to checking for a current draw, you can pull fuses and look for a drop. But if you suspect the trailer might be an issue you can unplug the trailer and see if the draw goes away. Assuming the trailer plug has the 12v power pin that feeds power from the truck to the trailer. Make sure you don't have something on in the trailer that is drawing power. For example I pull a few different box trailers and they have interior and exterior lights on switches that are powered from the truck through the 7 pin connector. On my Ram there is power whether the truck is on or off, or even if the key in the ignition etc.... Basically my truck can be off and locked and you can walk up to the trailer and turn on the lights, which would obviously drain the battery. On some vehicles they will not give power to the trailer connector unless they are on, or at least the key is in accessory mode.

 

[Tominator223]

Check that trailer plug. Truck side. You may have corrosion in the plug. Then plugging it in & unplugging may have disturbed it enough it’s not a problem now. If it’s a mounted plug check the back of it as well. The corrosion could cause a short resulting in parasitic lose

 

[carlos22]

14.2 volts shows that your alt. is good, tells you nothing about current draw when turned off.
Regarding current draw, you don't check it when anything is turned on, most meter will handle 10 amp.
You let the truck sit with everything turned off for a couple hours at least to let the computors go to sleep.
best way is use a jumper on the battery post and battery, and meter hooked up the same way.
then unhook the jumper cable or just pull the b+ cable off the battery with the meter on amps.
it should read about 40ma . trailer unhooked of course, everything shut off. don't open doors and leave the key fob in the house.

If you have a battery in the trailer, that could be killing the truck battery, or fridge, electric brakes, etc.

So shortly after that my battery went down to 9-10V and upon restarting the truck the battery dropped to 8V. While running the truck said the battery voltage was 13-14V but then turning it off and having the key in the on position the battery was dropping to 8-9V. Dangerously low, I don't think my battery was charging at all so I replaced my alternator. I think the readings from the other day weren't accurate because I charged my batteries 2 nights prior. I think my problem was the alternator, while driving about 25 miles I stopped for gas last week and my charge was dropping everything I turned the truck on. I think that was the problem, the autoparts people probably did my test wrong.

 

[Marshall]

Unhook the battery, and then check the voltage.
You could have a shorted cell, new fangled digital load tester will miss that sometimes from what I hear, I don't have one, had the old style with a big old shunt in it, like a toaster.

When you are checking current draws, you can't have anything turned on, unless you have a hi current amp meter, and not really going to tell you anything as with the key on, everything is drawing current. Charge battery up and leave unhooked and check it next day, or get it load tested again.
My Car battery dealer said it was OK, still under warranty, It would go dead in a week or 2 .
Canadian Tire checked it and showed bad. Been good after I bought new one.

I was running a small battery maintainer as the car would sit for long time , but don't need it now.
I should move it over to the truck as the battery is still original in my 2014
BTW if you are showing 8 volts , your battery is dead as a doornail.

 

[Mark DeRoncey]

This started as an inquiry into whether my battery was dying due to the trailer 7 pin being attached. We'll I've disconnected everything and have been sitting here for a while. I've also made sure my inverter was off. However after maybe 5 min, the dash goes out and then a few min later it comes on again. I made sure the wheel for the dash lights is all the way off and my key is out. I tried to start my truck again and it was struggling as if the battery voltage was low. Also when I pulled codes, the only one there was for low battery voltage. If anyone has had this issue before let me know. This is a 2017 Ram 3500 Tradesman 6.4L V8

Check your under hood light. I had the same issue on my 1500. Could not figure it out, went out late one night and saw a light under the truck. The light uses a weighted switch and one of the clips had broken preventing the light from turning off.

 

[CaptOchs]

Does anything not work? Power windows, locks, etc... My old Expedition had parasitic draws a couple times. First time was a rear windshield wiper that seized. The motor was running until it froze. It wasn't until I figured out the rear wiper wasn't working that I traced that one down. Another time there was a door sensor. Kept turning on lights because it thought someone had opened the door while parked. Sometimes it's the little things.

Regarding the trailer plug. It shouldn't charge if the motor isn't running unless someone change it. Most trucks now require you have the engine running for the relay to charge the camper battery. Some like my dad's F150 requires the truck be at least 10 mph to charge.