after driving my jeep for the weekend, I went to start in Monday Morning and it would not start. I had nothing, no lights, no electric door locks nothing. I was able to jump start it with another vehicle and a jump box and it started. I charged the battery and attempted to start it and nothing. accessories will come on, but as soon as you try and start it you hear a click and everything goes dead. i figured the battery was bad, and it is still under warranty. I took it in for an exchange and they tested it and told me it was good. I tried it again and nothing. once jump started it will run without a battery at all and the alternator is putting out 14 volts. Is there any type of regulator or anything that would keep the battery from starting the truck, bad ground etc. I was sure it was a bad battery since you can jump it. it was a Walmart who tested it. after running for 20 minutes, i turn it off and nothing, it does not even attempt to start just a click

 

The power is not getting fully to your starter. I think it is the cable...

The power cable may have some bad voltage drop, and may need replacing? Or, maybe there is too much ground resistance?

Possibly it starts when you jump it because the donor vehicle with its alternator going is able to overcome the voltage drop in the power cable.. Or, the ground resistance?

It does sound like bad terminals, or a connection at the battery to me too though.. since you've lost power to everything at times.

 

Make sure the battery terminals are clean and tight. Wire wheel or something to the posts on the battery, and an abrasive pad or something to clean up the insides of the battery cable terminals where they contact the posts if you haven't done that...

Next, I think I would start with cleaning up the three wires at the starter. Disconect them and clean these connections up here with a wire brush or abrasive pad.. Hook them back up and see what happens?

Make sure you disconnect your battery before you mess with the starter wire connections.

 

One more thing..

How did Walmart test your battery? If they did not load test it, there is a very good chance it could be reading normal, but still be a BAD battery. That sounds like what it is...

You said the battery is older and is due for replacement. Pull a known good battery from whatever vehicle you can, hook it up to your jeep, and see if it starts your Jeep?

When everything was dead.. When you get nothing but clicking starter.. Did you test your battery to see its state of charge when these things were happening?

A bad battery may even read say 12.65V, and be bad still to cause the starter to be unable to crank and turn over the engine effectively.

I think you have a bad battery?

 

the battery is less than 3 years old. Walmart did a load and volt test and it past. im not getting a clicking starter, I get 1 click then everything goes off. I will find another battery and see if it will start. thanks

 

1 click..
Then, all power is dropped dead? No lights, gauges, electric of any kind?

Or, 1 click..
Then, all power is still present with full headlights, gauges, full electrical power... Just no more click? Does everything dim (turn on the interior lights and gauges brightness) when you attempt to start?

 

1 click and everything is dead

 

I've had the same thing happen with a full loss of electrical power, hearing a single click first, and then everything was dead.

Only one time it was a bad starter.. Several times it was because of bad battery cable terminals when it happened to me.

If you know the battery cable terminals and the battery are good, it is possible you may be looking at a bad starter?

(edited to add):
I had to go back to add this. Almost everything I read online says that a bad starter, solenoid, or starter relay won't cause a loss of electrical power. I guess this is ussually true? I replaced my battery at the same time as replacing my starter (a 6 - 7 year old battery at the time).. So, I may not have had any power because in my case the battery died finally at the same time? I think my starter was weak, and the two were actually killing each other is what it was? Mine stopped responding and would not start with a jump after the first one or two times though...

A bad starter is not supposed to cause a loss of electrical power. Unless, your battery is that bad and may already be close to gone.

If the above bold statement is true? Then, what you have going on is unussual. It is not normal to drop the electrical load like that if the battery, cables, and battery terminals are fine on a good battery.

 

I feel kind of stupid, but it was the battery cable terminals. the posts on the battery and the terminals did not look corroded but I cleaned the crap out of them with a wire brush, connected it back and it fired right up. Originally I cleaned the battery posts but not the cables. I guess it was not able to make a good connection. thanks for all you responses and help

 

There it is. Don't try to eyeball electrical connections. You must take them apart to properly inspect them, and since they are apart, it would be crazy NOT to clean them thoroughly.