possible bad alternator?

[GumbyJarvis]

So a few months Back in my truck, well a year ago, I put in a sub box/amp. Last few months my truck has been occasionally bogging around so to say. Occasionally I'll drive 20+ miles and go in a store to come out to a truck that won't start and the inside light will keep clicking on and off. I have to disconnect the battery and reconnect it for the truck to start. Not an issue until one time it died at a light.. This morning I got in my truck, radio, ac and headlights on, the truck bogged down like it was going to die but I quickly shut off the ac and radio And it ran somewhat better. Question is I know it ain't tye battery, its not the clips on the battery as I change em once a year due to Florida weather and the battery was just replaced. Could it be the alternator?

 

[The_Jeff]

It could be or it could be the battery even though it's new. I had a battery with an intermittent shorting cell and the alt output was not enough at idle with the headlights on, just as you describe.

You've got to get a voltmeter on it, rig it up to the cigarette lighter.

 

[Rand]

how big is the amp you put in.

 

[AuthorEditor]

Could be the alternator, but I would still have the battery checked out even though it is new. I have had brand new batteries that wouldn't hold a charge for some reason. My local autoparts place will test both the battery and the alternator for free. You could have a short or draw somewhere that is depleting the battery between starts. That is the most likely after a bad connection.

 

[Jim Spahr]

Of course, check the output of the alt. But it sounds like the alt. is good, it just can't keep up with all the demands of the new sound system. You need an alt with a higher output.

 

[GumbyJarvis]

1200 watt amp

 

[GumbyJarvis]

I've also had this box for a year or so. No problems till about 6 mos ago

 

[UNC017]

I think its almost impossible for this to be the alternator. Its something with the vehicle. IF it were the alternator, the battery would die so that disconnecting and re-connecting the battery wouldn't cure the problem... the battery would still be too dead to start the car.

Probably an issue with hacking into the wiring to install the sheet-metal-rattler.

 

[mechtech2]

Originally Posted By: 440Magnum
I think its almost impossible for this to be the alternator. Its something with the vehicle. IF it were the alternator, the battery would die so that disconnecting and re-connecting the battery wouldn't cure the problem... the battery would still be too dead to start the car.

Probably an issue with hacking into the wiring to install the sheet-metal-rattler.



This^.
The evidence is that components were installed, and now things won't work right.

 

[AuthorEditor]

Quote:
I think its almost impossible for this to be the alternator. Its something with the vehicle. IF it were the alternator, the battery would die so that disconnecting and re-connecting the battery wouldn't cure the problem


I agree it is less likely to be the alternator, but batteries do "bounce back" somewhat. More than once I have started an engine with a seemingly flattened battery by letting the battery rest for awhile between attempts. The alternator could be putting out enough to modestly charge the battery when you have few accessories running, but not enough to keep up when you have the lights and amp on.

 

[GumbyJarvis]

So, I dont have this issue with only 3 things on, I guess no Radio, Wipers, Defroster and Lights at once for me!

 

[Scott_Tucker]

It sounds like a problem and the terminal clamp.

 

[Scott_Tucker]

Sound like a terminal clamp issue.