Hey guys, I have another problem I'm sure has been discussed before but I want to make sure I get the proper advice on where to start, as I don't have lots of time to spend on the truck lately;
A month or two ago, the batteries started having problems while driving. The voltage would drop to the point the truck finally quit, dead in the street. I had to get a bud out to jump the batteries just to roll the windows up and then sat there for an hour before I could start her again. After a ten minute drive home she was again, completely dead. I am super busy at work right now so parked the truck and used the secondary for a daily worker the last few weeks. I did charge the batteries when I got it home and they started the truck and ran, idling no problem. Still,I needed to haul some weight and materials today so I turned the key yesterday, and after sitting for AT LEAST a month, she started right up, so the batteries are holding a charge for some time when not running. I charged the batteries again yesterday just for good measure and she cranked right up at 5am today. I ran about 300yds to our site office and shut her down, loaded the truck then tried to start again, NOTHING! Not even enough to crank.
Now, here are some details; I have an aftermarket 200Amp alternator on the truck with less than a year of service and probably around 2,500 miles. I checked the voltage on the pin on the back where the big wire comes out and it read 14volts running. I don't know if this is only reading the voltage of my batteries or what the alt is putting out, in volts. Should I be checking the amps, or somewhere else?
Second, I have two Duralast Gold Top, 900cca batteries on there with also about a year, more or less of service. They hold the charge when not running but not sure that means they are still good. I don't see any reason why the batteries or alternator should've failed yet.
I am wondering, those of you who know vehicle electrics and troubleshooting, cause I certainly don'e , should I be looking for a faulty keyed ground somewhere? I mean a ground on a wire that is only hot with the key on, or is this something more simple, like the batt's or alternator?

Thanks much, as always for any and all input.
I will report back with any findings.

David.

 

when this happened where the batteries completely discharged? Meaning did you test them with a multimeter?

I'm assuming loading the truck didn't take that long so to completely discharging the batteries would take some serious current draw.

I am kind of wondering about the connections at the starter? And just to be sure how are the connections at the battery's? I would also be suspect of the starter, I have seen bad starters/started solonoids that would leak current causing battery discharge.

 

I agree with Clem1226, check your starter connections. If they are good, you might try charging up the batteries again to get the truck started and then feel your alternator. Is it hot? With engine running, pull the connector plug on the alternator (briefly) to see if you can hear a change in load. A 200 amp alternator should have some sort of effect on the engine when charging at full amps. I am not sure how the regulator works but overcharging a battery will kill it pretty quickly.

My truck eats batteries every 2 years without fail. I am not sure if it's the cranking or the re-charging that is doing it but they just don't last. I suspect the method of regulating the recharge rate is my problem but I really don't know for sure.

My vote is that your batteries are shot. (just guessing though....)

 

Good question, no I didn't test the batteries. I had to get to work and just ran to pick up the other truck. It literally ran about 5 minutes or less and wouldn't tun over, except maybe one or two revolutions, so as dead as can be. The loading was done with the truck not running but the batteries are definitely not discharging while not running, so it has to be the five minutes that killed them. I was always under the impression there was no real draw on batteries once the truck is running, isn't that true? I had on no A/C, not even radio. ????

It's been pouring rain all day so haven't been able to check the starter but will look at those connections as soon as it dries out, thanks.

David.

 

I really hope you are wrong but tend to agree with you. I have had batteries last me 5 years before so was hoping for the same again, not one year. I cannot return or get any warranty on them and shipping them in is expensive so that is gonna really suck.
I think all the alternator connections are via bolt on connectors so don't want to pull them while it's running as I don't want to arc anything but I will feel to see if it gets warm next time I can run it. I assume it SHOULD be???

Cheers, David.

 

I am sorry, but I dissagree. IF you were charging the batteries, and overnight you were not able to start, then yes, maybe the batteries or a load on them. But you are able to start, and drive, then your truck dies? That to me would make me want to check your alternator out..

Your truck should be able to drive all day with the batteries disconnected, not that I recommend that, so if you are dying, while driving, check the alternator.

 

Will do. The center of Tropical Storm Alex just passed over us so it might be a couple of days, but I will do that.

Thanks!

 

Sorry for the rookie questions AGAIN guys..... I noticed this morning as I went in to test the alternator that the second battery (drivers side) negative terminal is loose. Still have sleeping neighbors so haven't run it yet to see if the voltage drop still comes but could this be THE problem, or would it only be a part of it?

Cheers,

 

If you were having problems starting, absolutly.. But what you are saying, it says to me that the alternator is failing. The truck should run all day on the alternator, with out the batteries. While you are there, go ahead and clean up all of the post though.

By the way, I have always had to replace my batteries with in a month of replacing my alternator

 

Thanks a lot Pat. I saved the 'How to Rebuild your Alternator' thread in my truck folder and will check it out later, but for now..... If I pull the alternator, even being a fairly new one and start to take it apart, am I correct in thinking any problem should be able to be found *visually* unless it is a simple electrical component like a diode? If that is the case, I will pull the alternator today and have it checked out properly and take the opportunity to replace the water pump which just started to leak. Maybe I should do the coolant filter add on I have also while I'm at it. Oh dear, here we gooooo......

 

I am certainly not an electrical expert by no means, but this smacks of a bad ground situation to me. If the alternator is that new and the truck intermittently won't start, I would think ground issue right off the bat. That and the fact that I think you are on an island, if I recall correctly, makes me think there may be a corrosion situation going on. These wires are not sealed and are subject to the elements. The fact that one of your ground terminals was loose goes to that bad ground theory as well.

 

Jason,

Maybe I misread, but what he said was as he is driving, it dies. And then there is no power to start it.

A rebuild of the alternator use to consist of bearings and brushes, I dont know what they are doing in there anymore for a rebuild. Rebuilding them is fun, but if you go out and get one, you have the warranty.

 

Jason & Pat, thanks. If you read the end of my first post I think either of you, or both, could be right. I wondered about the possibility of a bad ground on something that only gets juice when the key is on as that is the only time it draws the batt's down, but then I am now leaning toward what Pat was saying and thinking the alternator (and next the batteries) could be to bame. I think I'll be repairing or replacing both soon, either way.

Been bogged down with paperwork/ billing all day today but hoping to get to it tomorrow and will definitely report what i find. In the meantime, pls keep any suggestions coming.

 

Btw Jason, you are right. The salt here eats everything! I am on my third positive battery terminal in a year on the backup/ work truck.