Alternator?

[97LTD]

Today, while driving to work, just noticed my battery gauge started to fluctuate and the needle dropped near the low mark. When I came home from work... the results were the same, and the lights dimmed when the needle is near the low mark then went back up and light become brighter then dimmed.

Is this a sign of alternator going out and it's time to replace it? Btw I got a new battery last fall after 9 years (Motorcraft brand) Good life... I replaced with the same Motorcraft brand. I don't think the new battery is the issue.

Thanks!

 

[Flash]

I reckon the first place to check is the battery terminals.

Look at this thread.

 

[97LTD]

Thank you...I'll check the terminals and get it tested.

 

[mr_valingo]

Terminals, battery, alternator, or a system short

 

[97LTD]

I got it tested and it turns out to be alternator that is weak charging. Am going to get new one to replace it.

Thanks for the help guys.

 

[Flash]

You probably just saved yourself the cost a battery as well by attending to it quickly.

 

[mr_valingo]

You probably just saved yourself the cost a battery as well by attending to it quickly.

Or at least shortened its life so it dies within the warranty period

 

[Flash]

Or at least shortened its life so it dies within the warranty period

There's that.

 

[97LTD]

Yes, very fortunate. I was able to drive home from work last night and I was surprised that the Explorer did not die on me and needed a tow.

The battery was tested and passed. it turns out that the alternator had zero output. So I bought a new one and changed the alternator. Passed the test with 14.5 volts with the engine running. Everything works good and the battery gauge stays where it is, no fluctuating.

Appreciate your help

You probably just saved yourself the cost a battery as well by attending to it quickly.

 

[97LTD]

Well since I had the alternator replaced back then... now I think it seems to be acting up.

When I am at a stop or idling, the battery gauge drained, when I'm on the go, it's all normal.

This doesn't seem normal to me, whether the new alternator is defective and it shouldn't drain like this at idle. If it is, then I'd have to do a part warranty replacement again.

Thoughts?

 

[jremington59]

Is the belt tensioner keeping the belt tight? Any squealing noises? Check the voltage to the battery at idle.

 

[1996BLKBauer]

Belt tension could be the cause, when mine did the same thing as your original story, it also destroyed the belt, because it was actually locking up, so the belt wore out, and it was already pretty old. But anyway, a worn out belt, even though it looks ok, can still slip under load, but once again could be a junk ALT, the reman ones now a days are garbage.

Check the belt, most auto parts stores usually has a small orange tester from Gates to see if multiple grooved serpentine belts are worn out. Also, since it only take 10-15 minutes to remove the alt anyway, might as well have it checked.

 

[97LTD]

I had the new belt installed a while ago..the old belt had almost 60k miles on it and had a sign of crackings. Took it to the shop and a test with engine idling and giving it gas, the voltage was 13 volts which was low. With the warranty, now the Explorer has it's 3rd alternator, hopefully it will hold out.

I wish there would be a new parts out there instead of remanufactured. It's much easier to use new parts instead of rebuild.

 

[SoNic67]

It might be something in your system that kills them. Charging an 'empty' battery will kill an alternator. A big amplifier cranked at max will kill it too.
I got my replacement alternator reman, but from the ones with 'lifetime warranty'. No issues.

 

[koda2000]

I had the new belt installed a while ago..the old belt had almost 60k miles on it and had a sign of crackings. Took it to the shop and a test with engine idling and giving it gas, the voltage was 13 volts which was low. With the warranty, now the Explorer has it's 3rd alternator, hopefully it will hold out.

I wish there would be a new parts out there instead of remanufactured. It's much easier to use new parts instead of rebuild.

parts stores carry new as well as reman alternators and starters. new ones are much more expensive (and not worth it in my opinion). i've used remans all my life without any problems. even a new unit can be defective. like sonic said, running a bad battery, or big amp, can kill an alternator.

 

[97LTD]

It might be something in your system that kills them. Charging an 'empty' battery will kill an alternator. A big amplifier cranked at max will kill it too.
I got my replacement alternator reman, but from the ones with 'lifetime warranty'. No issues.

I had a new battery put in last spring and it passed the test so it seems to be OK. If this happens again, I will ask to diagnose it.

parts stores carry new as well as reman alternators and starters. new ones are much more expensive (and not worth it in my opinion). i've used remans all my life without any problems. even a new unit can be defective. like sonic said, running a bad battery, or big amp, can kill an alternator.

That'd make sense about new parts are more expensive. Sometimes reman are good, some don't last long with defects. I took mine to Ford dealer and they use Motorcraft alternators. If this fails again is there any good aftermarket brands that I could look for?

Thanks for the tips!

 

[koda2000]

I had a new battery put in last spring and it passed the test so it seems to be OK. If this happens again, I will ask to diagnose it.




That'd make sense about new parts are more expensive. Sometimes reman are good, some don't last long with defects. I took mine to Ford dealer and they use Motorcraft alternators. If this fails again is there any good aftermarket brands that I could look for?

Thanks for the tips!

Ouch! you had the Ford dealership install a brand new Motorcraft alternator? what did that cost?

 

[97LTD]

Ouch! you had the Ford dealership install a brand new Motorcraft alternator? what did that cost?

I think alternator was around $250 + labor. I am aware it is expensive but fortunately I had warranty for the 3rd alternator and I paid nothing.