Need help! No start

[jd92887]

I was driving my 04 today, and the radio turned off an back on a couple times. Then I parked and tried to start it after a few minutes, and no start. I was a blue to jump it, but while I was driving I had no gauges no radio, no power at all. Now it won't even jump start.
I put a different battery in(from another car to test) and it started, but when I disconnected the terminal to see if it would run with no battery, it died immediately.

The battery is from 11/08

 

[D Hook]

While it was running, did you put a volt meter on the battery terminals to see what the alternator output was reading? Should be around 14.5 volts.

 

[jd92887]

I had the alternator and battery tested they said the alt was bad, and the battery was low. I replaced the alt and it ran fine for a while, then the battery light came on and it is acting the Same as before I replaced the alternator.
Right when I replaced the alt, I could take the battery cables off and it still ran, but now it doesn't do that.

 

[D Hook]

A bad battery can ruin a good alternator. Anyway, that's been my experience.

Did you replace the battery when they told you it was low?

Did you put a voltmeter across the terminals to see if the alternator was putting out the correct volatage? If you don't have a meter, you can get one at Harbour Freight for about $6, IIRC. Don't forget, the autoparts store would like to sell you an alternator. Then, after the sale, they have little interest in testing the new one, since if it's bad, they'd need to replace it. Do the test yourself then you're sure of the results. You should be seeing around 14.5 or so volts DC.

May have gotten a bad alternator. Not unheard of. You need to check the voltage output to see what's happening. If you can't get it started, you'll have to remove the alternator to have it checked at the autoparts store.

Be careful about pulling the cables off while the vehicle is running. While it might not do immediate damage, I've been told it's not a good thing to do for either the battery or the alternator or the vehicle electronics.

 

[jd92887]

They charged the battery for a couple hours, an I charged overnight too.

Went back, to have the alternator tested, and their tester was broken, but they still changed it out for another one.
Tested the battery again, and it was good, 13.3 volts
Installed new alternator and I put in a battery from my other explorer, also didn't hook up my amp power wire. Gonna see if it works for a day or two, then hook up amp wire.

Maybe the battery has a dead cell causing it to short? I don't think advance auto can test that but I'm not sure.

Working for now.

 

[D Hook]

Very possible. Is the battery anchored? Sometimes a loose battery will bounce around and make the plates loose inside and short.

Are you driving a large sound system? That can also put a big strain on the batter/alternator. Your'e smart to leave it disconnected for a few days and see if there's a difference in performance.

 

[KamiKaziDK]

Sounds like a weak cell in the battery to me, what do your lights do when you go to start it?

 

[jd92887]

It's just a 1000 watt amp, and yeah the battery is held down.

 

[DJ]

Sounds like a dead cell to me. In my experience if 1 goes (alternator or battery) the other one usually goes. I've seen a good battery go bad from a dud alternator and I've seen a battery with 2 dead cells kill an alternator.

My autozone, although sometimes an uphill battle, will go out to your truck in the parking lot and hookup a voltmeter. Then they have you start the truck and watch what your alternator is putting out. I replaced my alternator yesterday, because when they tested it, my battery was fully charged. However my alternator started by putting out 11.9, but after a whopping 30 seconds had dropped down to 6.3.

In the past though they have been able to tell me if I have a dead cell......... just saying.

 

[DJ]

It's just a 1000 watt amp, and yeah the battery is held down.

Although I doubt this is the issue, it couldn't hurt to disconnect power temporarily until you find the culprit. It just takes something out of the "why the hell would that cause that" category.