Ranger stalled, alternator replaced - need new battery too?

[nadsab]

Our ranger just stalled out while driving, I suspected the alternator and repair shop comfirmed. I would have replaced it myself but we did not have the time and were left stranded.

Anyway the truck always started fine no problems but the problem occurred out of the blue yesterday, when the engine started sputtering while on the road, radio intermittently went on and off, engine sputtered to a stall.

Shop replaced the alternator and they said we also needed a new battery but I think the battery is OK because it always started up fine no problems. However mechanic said the bad battery can burn out the new alternator if we don't replace it ASAP, so if needed I will buy new battery and put it in myself.

So we are going to pick up the truck today, if the truck starts up AOK, does this mean the battery is OK? Or is there a simple kind of test I can do to check the battery?

I was wondering if maybe the internal resistance of the battery is high and causing the alternator to over work or something like that? Or maybe it's a short to ground somewhere?

Thanks for any info or suggestions.

 

[shane96ranger]

Before you go wasting any money on a battery, I would check your ground connection on both sides of the cable. Also, take the battery out of the truck and have a load test performed on it. The load test is free at several auto parts stores like Autozone.

 

[nadsab]

OK thanks.

Could a bad ground connection to the battery itself damage an alternator?

Also on the load test, do auto parts stores do that in front of customer so we can see the results or do they do it in the back out of view?

Curious because we know they want to sell batteries LOL.

 

[shane96ranger]

OK thanks.

Could a bad ground connection to the battery itself damage an alternator?

Absolutely.

Also on the load test, do auto parts stores do that in front of customer so we can see the results or do they do it in the back out of view?

Curious because we know they want to sell batteries LOL.

The Autozones here do all testing at the front counter (alternators, ignition modules, starters, batteries). They can actually do it in your truck as well, but I wouldn't want to risk ruining your alternator if your mechanic is correct.

 

[nadsab]

OK great thanks shane96ranger I will keep that in mind,

I am now starting to wonder if instead of a bad alternator, maybe all we needed was a new battery?

Could the original symptoms I posted above be the result of only a bad battery?

 

[shane96ranger]

In my experience, I've never seen a battery intermittently work. It works, or it doesn't. Maybe somebody else (there are a couple of members who work at battery stores on here) can tell you different, but I've never seen it. I would suspect a bad ground first if I had your symptoms.

Was your battery completely dead when you took it to the shop?

 

[nadsab]

Well that is the problem I am not absolutely sure if the battery was dead at the shop.

My wife was driving the truck and got stranded and after the truck stalled out she did not try to re start the truck and just waited for a tow.

BUT, that morning when she left for the day before the stall out - the truck started up just fine - started right up as normal...no problem...

 

[shane96ranger]

If the battery was dead, then it very well was the alternator. Once the alternator quits working, it will run on the battery until it's dead.

 

[nadsab]

Ok thanks.

And if the battery was not dead, could the above symptoms of the truck stalling out just have been caused only by a bad ground connection from battery to chassis? And not a bad alternator?

 

[shane96ranger]

Will your shop tell you if it was not dead? It sounds like they want to sell you battery, LOL.

 

[nadsab]

They did not actually say the battery was dead, they told my wife that if the battery was also not replaced asap that the so called bad battery could fry out the new alternator they just installed....

Could this be possible?

 

[shane96ranger]

If it does have an internal short, yes it could ruin the alternator. I would go get it load tested to see if their claims are accurate.

 

[nadsab]

Ok thanks, and I suspect, could a short like a bad ground also damage the battery in addition to the alternator?

I am starting to wonder though if maybe all this was, was a bad ground connection to the battery and that I may have not even needed an alternator at all.

Another question, if after picking up the truck (which we are doing right now) if it starts up fine, do you think that means that the battery is OK and it was only the alternator?

Lastly, what is the average life of an alternator? How long are they supposed to last?

Ours is maybe 5 or so years old and has somethwere between 80 - 120,000 miles on it...

 

[Earl43P]

Your battery is absolutely dead or the truck wouldn't have quit running.

For the new alternator to recharge the dead battery, it will put out its max output (regulated internally).

The shop could recharge the battery for you (with a charger) and then load test it.
My experience is that once an "old" battery gets completely discharged, it'll fail in the near future.

My advice is to replace the battery since it got completely discharged and will not be reliable in the future, even if the shop does charge it for you. It depends on the battery's age, of course, but if it is over a year or two old, replace it for peace of mind.

THAT'S the message your mechanic is trying to get across, a reliable repair so it doesn't "come back" to him..

And yes, a faulty battery COULD have contributed to your alternator failure (even though it reliably started the engine).

 

[nadsab]

OK thanks!

If the old battery load tests OK, does that mean it's safe to use for now?