F800 battery problem has me stumped

[ghunt]

I posted this in the big truck forum but I know there isn't a lot of traffic there and I have an update anyway...

OK, I play part time mechanic at my work since we only have 4 full time employees and one part time driver who is retired and only comes in when we call him. We have a '97 F800 powered by a 5.9 Cummins.

Truck gave us no problems until week before last when the temps went into the single digits over the weekend. The next week (with temps in the upper 30's at the time) I went to start the truck and it would crank slowly once, and then click click click click. The truck has three Group 31 batteries, two were one brand, the third was some other brand, and they all looked to be 4-5 years old.

I pulled the batteries and took them to Advance to have them tested. The two batteries that were the same brand tested ok...one tested at 800-some CCA, the other at 910. The third (different brand) battery tested in the low 600's so we got one new battery.

Well, I put them back in the truck today, hooked everything back up, and....it's still doing the exact same thing, one slow crank and then click click click click.

*** is going on? I would think a combined 2500 CCA would be more than enough to turn over that Cummins. I'm a little confused. I hooked a battery charger up to it for now but I just don't understand why it won't even crank.

 

[Dieselcrawler]

did you clean the terminals and cable ends? possibly a corroded terminal at starter.

how to the wires look?

 

[ghunt]

The cables look OK...the batteries are linked via two short, three post cables, and then the positive and ground cables attach to these and I'm wondering if that's where the problem lies.

Also, the solenoid was just recently replaced on the starter by a local mechanic we use and I would think he would have informed us if the cable end at the starter was messed up...

When I hooked up the starter I left the short link cables on, removed the battery cables and hooked the charger directly to the link cables. It was charging at 25 amps when I first hooked it up, then after a minute or so it dropped to 20. Not sure if that's good or bad.

 

[NJKen]

You gotta check all connections and take an amperage reading on the starter while cranking. You would be suprised how much current a messed up starter can draw. The starters used in these truck are not really the most reliable. We had a Freightliner with the ISB in it that ate a starter every year until I put a brand new one in it. It would start doing what yours is when it wanted to be replaced.
Ken

 

[iverger]

Just went through something similar. Had bought 2 new 1000cca batteries about the same time I did a bunch of other things. After a few days I started having the slow crank after an overnight sit and little chance of starting without a boost. I replaced the starter, alternator, regulator and all the cables. Same issue. I had taken the batteries to the place I bought them and to Autozone. Both told me the batteries we fine.

One day I had both batteries out, and on the charger. I noticed that one charged in 60-90 minutes and the other was never quite getting there. Convinced the place I bought it from to replace it and everything has been great ever since.

"One bad apple spoils the bunch"

Bob

 

[ghunt]

My question is how could something like a starter have just up and died over the weekend while the truck wasn't even being used?

I hooked the batteries to a charger for a couple hours today...no change...ugh, this is ******* me off. I noticed there is some kind of a ground cable that goes from the positive lead on the battery, to a post on the frame that almost looks like it has a fuse on it, then another cable comes off the other side of that post and goes off somewhere, I can't tell where. Where the cable connects to this post on the frame, the connecting lug is kinda corroded and has that green crap on it. Not sure if this would have anything to do with it.

The lights, radio etc all work fine but the truck will only crank over very slowly every few seconds.

I had wondered about those other two batteries also, I figured we'd just replace all three and call it a day but I don't know.

BTW the main battery cables look really good, even the steel posts only have the slightest hint of any rust on them.

 

[OLDBULL8]

The ground cable is the problem, lights, radio and so on take very little current, starters take 600 amps or more initially to start cranking. Clean those ground cable connection, remove the bolt, prolly see rust under them. Guarenteed fix or I owe you a dollar.

Another thing, you should never mix unlike brand batteries, never change only one battery even the same brand, replace them all at the same time, you won't be sorry.

 

[Dieselcrawler]

you didnt state what type of truck it is, but that other wire to the "fuse" is possibly for a tarp(if dump truck), a liftgate, or might send power into the cab.

 

[ghunt]

Oh it's a flatbed.

I talked to the guy who we have do the routine maintenance and big stuff on the truck and he seems to think it's the ground strap too...if it's not raining too bad tomorrow I'm gonna see if I can get a look under there and clean up some connections.

 

[MIDNIGHT RIDER]

OKAY; the engine is a 5.9/6BT Cummins, right ??

It most likely has a NipponDenso starter just like that found on the Dodge/Cummins.

When the starter contacts finally get eroded away, all of a sudden, all you will get is "click".

It may take ahold and crank enough for a few more starts and then only click the next time.


Read this :

http://www.dieseltruckresource.com/dev/showthread.php?t=141395



That should get you started in the right direction.

 

[MIDNIGHT RIDER]

I noticed there is some kind of a ground cable that goes from the positive lead on the battery, to a post on the frame that almost looks like it has a fuse on it, then another cable comes off the other side of that post and goes off somewhere

That CANNOT be a GROUND-cable if it is connected to a POSITIVE-post of a NEGATIVE=GROUND vehicle.

I had wondered about those other two batteries also, I figured we'd just replace all three and call it a day but I don't know.

Just about everyone that uses multiple batteries only ever replaces the one that is bad.

Even John D. Rockefeller would soon go broke if he discarded two good batteries every time the third one went bad.


Many times, I read the scare stories about always replacing ALL the batteries and never mixing brands, sizes, and ages.


In actual practice, on the many multi-batteried vehicles around here, both past and present, I have only ever singled out the suspect battery and only replaced that one, with never a bad experience, nor shortened battery life that I could tell.


I run mixed brands, mixed ages often by several years difference, and even mixed Group-sizes; I've done this for years and see no good reason not to continue.

 

[MIDNIGHT RIDER]

"One bad apple spoils the bunch"

Bob

That is the way parallel batteries work.

Total voltage will only be the average of the whole group and one that is not up to par will drag the average down.


The best way to test parallel batteries is to shut the engine off after being used enough to have the batteries in a good state of charge and IMMEDIATELY completely dis-connect the batteries, both from the vehicle electrical system and from one another.

Let them sit thus at least over-night, and the longer the better.


Then, using a simple digital volt-meter, test each one for voltage.

Each cell of a fully charged battery = 2.1-volts

Six cells times 2.1-volts = 12.6-volts.

The battery showing the least voltage is most often the culprit; and, often, the bad one will show more like 9-volts or so.

Replace that one and the others will be none the worse for the experience.

 

[Diesel JD]

I've seen a guy start a 1st Gen Cummins on a tiny crappy battery, granted that was in the summer here in Florida at about 75*F in the morning and 90 during the day when I saw it. Let us know what the fix is when you get it up and running.

 

[ghunt]

OKAY; the engine is a 5.9/6BT Cummins, right ??

The starter is new as of a few months ago...so I don't think it's the problem here.

As for that cable...well, it's a black cable coming off the positive post of the battery. What is it for then? Does it just send power to the cab or something?

 

[MIDNIGHT RIDER]

As for that cable...well, it's a black cable coming off the positive post of the battery. What is it for then? Does it just send power to the cab or something?

There is no way other than guessing for any of us to answer that question.

You need to follow the wire and see where it goes.

From your description, it reads like something that has been added on for some reason or other.

That something may or may not still be on the truck.

Like already suggested, it could have powered a lift-gate at one time or another.