Battery or Alternator?

[2001ExpSport]

A few days ago I started my X in the morning to goto work and it barely had enough juice to turn it over, but it started. It was about 15 degrees out, but it's never done this even at 10 below. So, I thought it was nothing and went through my day. It started fine for the rest of the day. It's my work truck so I drive it all day and probably start it up 15-20 times a day.
The next morning it did the same thing, barely enough to get it started, I mean BARELY!. After that, it was fine. It's the first start in the am that is the problem.

My question is, is it a battery problem or an alternator problem? I haven't tested anything yet. I have a multimeter so if someone could tell me how to test the alt for correct output I'd appreciate it.

I have an original battery and almost 40k.

I guess I'll have my battery tested on Wednesday.

What do you guys think?

 

[fox]

well you need to check them both, check the batt to see that it reads over 12v and then start the car if you can and check to see that the alternator is charging, you do that be placing the probes on the batt just like you were checking the batt only this time it should read around 13 to 14v. hope this helps.

 

[2001ExpSport]

Thanks Fox

 

[jimbo74]

do a carbon pile test on the battery.....temps that cold also cuase water to freeze and if you have anything other than a dry or gel cell battery (ie Conventional) then it probably has frozen partially

 

[Perry]

If you have it checked and everything comes back O.K. then you might check the "+" cable going to the starter.
I was having the same trouble so I got a new battery and that didn't help. I had them check it at the local auto supply and it came back everything was working right. Then someone told me the starter takes a lots of volts or amps to turn over and to check the wire. I checked and it is warn pretty bad at the terminal. I haven't changed the cable yet, but I think that is it.

Hope this helps..............

 

[Jason_25]

May just be corrosion at the terminals. You may want to clean them.....couldn't hurt.

 

[2001ExpSport]

Everything is clean and I have a stock battery so I am assuming it is dry or gel.

 

[Perry]

Matt, don't worry about it now, go out and PARTY!!!!!

 

[jimbo74]

Originally posted by 2001ExpSport
Everything is clean and I have a stock battery so I am assuming it is dry or gel.

a stock battery is most likely a wet or conventional battery...not dry or gel cell.... a gel cell is what an optima is...

 

[MSTNGGUY88]

A battery with a weak cell will do the same thing. That has been the problem every time I have encountered what you are going through.

 

[yob_yeknom]

It must be a battery problem. If the alternator was bad, it wouldn't be able to run for very long on just the battery's charge. Also the reason it cranks up easily after it's been driven is because the alternator charges the battery.

Sounds like you have a bad cell and your battery just can't hold a charge for an extended period of time.

 

[2001ExpSport]

I'm going to look into it.