65pacecar

But I wonder if something is draining them. I haven't started the truck in about two and a half weeks and it has been getting into the low 30's at night. Last time it ran and started perfectly, this morning I was going to drive to Paneras and jumped in the truck, it cranked slow a couple of times then just clicked like the batteries was dead. I had a portable jumper that had about half a charge, hooked it up and it cranked close to normal one or two revolutions and sucked it down too. I hooked up the battery Tender and the light came on red and is still showing they are charging after a few hours. It seems like a battery issue but the batteries are only about a year and a half old and both are Mopar Units. On a side note though, the previous owner also let this truck sit for long periods of time without running. Anything I need to look for or is it just bad batteries?

PChouinard

Sounds like bad batteries to me. You need to get a good charger on them for at a good while (like overnight or so). Then see if they have enough juice to start. Have them tested aafter charging to see if they perform under a load. If one battery has a bad cell, it will drain the other. I would change them both if you have to change one. When the temps start to get below freezing, you may want to think about heating pads under the batts to warm them up. They should work ok in the cold but the warmer the better..(to a point).

kelownadiesel

It could be the starter contacts as well.Both of my trucks had symptoms that sounded like bad batteries.The contacts and the brushes on both starters were shot and I saved having to replace any of the batteries

qwest

If you have a shorted cell, it will kill both batteries.

I had same problem, removed 1 battery ground and it started great,
guessed right the first time,

RustyBoltz

i had what sounds like the same problem, i had just gotten a new starter put in and my truck began to start slow and then got to a point where it would just click, well i thought it just had to be the batteries, but it turns out that i got a new, bad starter.
So I would say, put a voltmeter on the batteries, and you should get a reading of about 12.5 - 12.6 volts, if you get a reading above 12 volts, it's probably not the battery, check the terminals and check the connections to the starter. If all are ok, it might be your starter.

kelownadiesel

Why did you buy a whole starter?90 percent of the time it is merely the contacts on the inside.It is like 30 bucks to get them.

RustyBoltz

Sorry, i had gotten the starter rebuilt and the internals replaced.

lotero

agreed, but i did put new contacts in mine and was getting a slow crank/hard start about a year later and my starter was the problem

kwast

I don't drive mine every day and it will sit for 4-5 or more days at a time. I don't know if anyone else has this problem but mine is hard on batteries because of the ecu draw. Sometimes my short trips to town on weekends are not enough to charge back up completely and after a month or so I will have dead batts. you need to get a hydrometer and check your batts, then charge them accordingly ( 1 at a time ( mine take 4 hours each on medium amperage to get close to full charge)). once I do this, I'm good for another month or so. I may have more of a draw than most because I might have an ecm problem, we (my bud is an automotive electrician and I am an electronics tech.) are still trying to figure it out in our spare time. but in the mean time this is the case.
if I drive it daily or long distance there is no problem long or short term. and if I remove the ecm fuse when parked I have no problems. I'll keep u posted if we figure it out, just don't have time lately

If any one has any input it would help me aswell.
PS: I've got more problems with this truck right know than I can take, some thing seems to happen every week I seem to add the above "If....." line to every GD thread.

nickg

I'm curious have you load tested the batterys? cause it sounds like a bad one to me. That or your ECM pulls a heck of a lot of load, which makes no sense

jrs_dodge_diesel

times two.

I agree with nickg, you either have a bad battery (or two) or something on your truck is drawing power from the batteries when it isn't supposed to.

kwast

ya, we load tested them in august during one of the low times and they were good but we haven't tried since then. They have been good because of the number of long trips I have been doing on weekends.

Maybe tomm. or over the weekend we will check again as well as get an accurate reading on the draw.
Because of the batts load testing ok and the draw dissappearing with the ecm fuse out, we figure its something in the ecm? but we'll see??


65pacecar have you checked for a draw with a meter??

nickg

you say you pulled the fuse and the discharge stopped, I fiqure with a bad cell and the trickle discharge from the ECM (which should normally take 6months if not longer to discharge) thats whats taking out the battery...then again just a guess, if the batts load test fine, maybe its something else that is also powered off the ECM fuse