OrangeCounty12V

Hi Everyone, for the past three weeks, I've noticed that my truck doesn't start up right away like it used to. Normally it'll fire up on the 1st crank. Yesterday, my truck wouldn't start. the starter would crank over, but it seemed like i lacked the battery power needed to get the engine going. I noticed that the battery power meter was reading below 1/4. So I replaced one of the batteries (passenger side) since the driver's side battery was only a couple months old. The old battery that i replaced was an old piece of junk, that i should of replaced all together with the driver's side batt. Anyways to get to the point, despite putting in 2 new batteries, my truck still has a hard time starting...sometimes i fear that it won't start and the voltage gauge is a little bit over the 1/4th mark. Another thing that i've noticed, is that the needle on the gauge will go up and down, and my headlights, and interior lights will dim a bit, for the first couple minutes after start up. Once the engine is running, it'll read above the 1/2 mark. I think something is draining my battery, and it don't know where to start looking..and whatver it is that's draining my batteries must be power hungry, since both batteries are practically brand new. Ive had a sound system with amp and subwoofer for a year now, but i haven't had any problems with this. I have noticed that for the past three weeks also, that my abs light goes on and off. Can anyone provide me with suggestions on where to start looking? Thanks much

William

rustram96

I would have both batts load checked, having a new battery paired with an old one will often kill the new one since it is doing all the work, its best to change them as a pair. both batterys should be no less than 850 cca. as far as the lights dimming and voltmeter fluctuating, thats normal when the engine is cold as the manifold heaters cycle on and off while the engine warms up.Check that your shut down solenoid is pulling full up when the engine is cranking.also check that you dont have a fuel leak somewhere from the tank to the engine,the fuel heater connector is a common place for air to get into your fuel system making for hard starts and poor performance. someone else can chime in about the ABS light, it could be a bad wheel sensor or wiring, but im just guessing

Dartmouth 12V

rustram96 makes a very good point about replacing both batteries at once.

If you think that your batteries are draining down, try unhooking them when you leave the truck a few times and see whether the condition goes away. If it does, something is drawing them down, if not, you have another problem.

One thing that you should do is look at your battery cables. The ends tend to get really corroded. If that doesn't do it, sometimes you need new brushes in your starter but look at the other stuff first.

dozer12216

Might be good time to check cables for corrosion at all connections including starter.
Contacts in starter and brushes in alt are a possibility.

Dave Miller

Good points have been made. You can get better starter contacts and other starter problem stuff here and look around the site for links to good troubleshoot info on your problem:

http://www.fostertruck.com/dodge/default.htm

Here is a thread on this site with pics and stuff that may help:

https://www.dieseltruckresource.com/...d.php?t=192652

Dave

OrangeCounty12V

Thanks for all the suggestions guys. I'm thinking it's probably the starter. I cleaned the ends of my battery cables with a wire brush, and I noticed on gauge that voltage went up a bit (close to half way mark) but still, the truck would start, and starter and the engine would crank over..but that was it. After a couple times of doing this, now the starter won't even crank over, it just makes a clicking sound. Many of you have mentioned changing the brushes and contact points of the starter. I'm mechanically challenged, but I have a friend that's helping me out. Is this difficult to do, and are there instuctions online on how to do this. Or am i better of just buying a new starter? I appreciate everyone's helping hand.

William

TreeFarm

Sometimes when a starter just makes a clicking sound, it's simply dirty and in need of a cleaning and lube. I'm not saying that is necessarily what is happening in your case. It's just something to keep in mind.

Dave Miller

Go to that web site I gave you earlier (and posted here again) for pics and description of how to do starter contacts:

http://www.fostertruck.com/contacts_install.htm

Take a look. Its pretty easy to remove starter. I've done it. The space is a little cramped but crawl under drivers side behind the wheel and look up at engine above oil pan at rear. Be sure to disconnect both batteries at either gnd or positive post will do. Here is a pic from that site of the starter and what it looks like in the contact area:

justme-

After having the batts load tested have the Alt load tested. The mismatch on the batts will often also overload the alt. Remember you always replace all batteries in a multi battery system at the same time with the same exact battery- so if you put in a different rating or group battery that could be you're problem, if not it will be. It's not just the older versus the newer mismatch that causes problems, it's the 1000CCA discharging into the 900CCA on the other side too.

TreeFarm

Matched batteries purchased at the same time is the proper way to go. That said, I have never had a problem with paralleling different sized batteries, and I have done a lot of it. As long as both batteries are the proper voltage and each is in good condition, then you should not have any real problems as long as their combined capacity is adequate for the job at hand, and they are both of the same type (flooded cell, gel, AGM, etc.).

justme-

You've been lucky. The physics of it dictate a Group 84 and a Group 82 will mismatch and cause issues, at minimum inefficiency and reduced lifespan of both batteries. I'm on a site for snowplowing and this is a hugely common topic, more commonly about isolators verses non isolators, but the same issue. The consensus there supports the theory, just as any reputable and competent battery dealer will tell you.

TreeFarm

I didn't mention any particular groups, so I don't know why you mentioned 82 and 84. What particular physics are you referring to? How about a detailed explanation how the lifespan will be reduced if they are not exactly the same size?

Battery isolators are used to isolate batteries. If isolators are involved, the application is entirely different than batteries simply wired in parallel. Unless there is a paralleling switch, the batteries are not connected in parallel, so I don't see the relevance at all.

The main concern in paralleling batteries is their charging characteristics. If they are not the same, there will be issues. As long as they are of the same type, and ideally the same age, there should be no charging problems.

Again ideally, they should be identical batteries, purchased together, but it's not the end of the world if they are different sizes, just as long as they are of the same type.

Experience bears that out.

Dave Miller

I believe that both batteries are in parallel. I've studied this when in electronic engineering school many times. Positive post to Positive post and both Neg leads are to Chassis Gnd. The current is double one battery but voltage is the same as one battery (12v) because they are in parallel. If they were in series then you would have postive to neg and one neg to chassis gnd and one pos to chassis gnd providing 24v and the same current as one battery to the system.

What am I missing here about your paralleling discussion? Just want to understand what you mean. BTW I agree that both batteries ideally should be replaced together and thats what I do...kinda expensive tho. I'm not sure if the characteristics both need to be the same but it sounds reasonable. I think if you replace only one then the good one can possibly get less charge and be pulled down to the old battery level. Just my opinion without proof based on my experice with batteries years ago in the Air Force.

Thanks,
Dave

justme-

Unfortunately batteries are one of those subjects everyone has an opinion on based on something- experience, school, an uncle who saw a friend..... The other unfortunate aspect is there is a lot of mis-information which gets perpetuated by people who don't know any better, or don't notice the effects and thus don't realize or don't believe the facts.
If I tell you the sun just exploded and you look up and see it in the sky and think either I'm wrong or seeing things. Sometimes it takes time (like the 8 minutes it takes for light to reach the earth from the sun) before the effects are obvious- and even then, some will say "No, it's just night time".
I mentioned those particular groups because I know them and they are similar in "size" yet different in specs. Charging and discharging characteristics vary by group, not just type with type (wet cell, dry cell, gell cell, spiral wrap, flooded, AGM, etc.)

The simplistic details are that different groups are made different ways- more or less plate material and more or less electrolyte. Each group, then, will discharge at a different rate, and charge at a different rate. The issue is that batteries in parallel tend to equalize their potential- meaning when you start the engine you create a draw, different groups (or the same group but different age- I'll detail later) feed that draw at different rates thus each battery has a different potential value after the draw ends.

Now, leaving the system alone in nature, which is to say you do not draw any more off and do not recharge them (no lights, no alt..) the battery with the higher potential (charge) will equalize with the battery of the lower charge. Batteries are designed to be discharged either a lot before charging (deep cycle) or very little before recharging (starting battery) and the mismatch can bring a battery below it's happy percentage of charge.

Now, let's go back to the real world where as soon as you start the engine we're also charging the batteries back up- Remember each battery has a different discharge rate so they have different levels of charge. Not only will it take longer for the "lower charged" battery to reclaim a full charge, one battery style may take longer to recharge because of it's design and construction. So, batteries in parallel are a single big battery to our charging system- the alt and ECM don't know there are 2 batteries, nor do they have any way to isolate them from each other, the temp sensor under one battery proves it- they only monitor one battery for overheating caused by overcharging.
So, the alt charges at the rate the "system" needs feeding the lowest battery at the rate it needs to be charged at. The result is the battery that charges faster gets overcharged while the slower charging battery still needs charging. This can overwork the charge circuit (regulator circuit), the alt which will charge 'HI' longer than necessary, and the battery which is overcharged. The inverse can also happen where the regulator senses a balence voltage (basically the average of the 2 batteries since it sees them as a single battery) and stop charging before the slower/lower charged battery is fully charged.

Now, with regard to older batteries, as batteries age they sulfate and the plates are consumed. Both conditions means less plate surface area exposed to electrolyte which effectively changes the characteristics of the battery to the same degree a different group or size will. So it's not "Ideally the same age" but a MUST BE the same age. I've seen cells reverse polarity because the battery was not charging from age.

The discussion of isolators if from the plowing board (if you reread my post...) where most guys have gassers and single batteries but want to add a second to take the brunt of the plow's demands and think the isolator is going to be the answer (it's not really in most cases).

Make sense?