Okay apologies in advance but kind of on a time crunch on this one. Got my 05 LR3 16 days ago from a dealer up in Albuquerque, 103000 miles and in decent shape, so I thought... So here's the story.... It just spent 10 days in stupid heat at long term parking in El Paso airport parking, did the 90 mile hike home just fine, did a Walmart pit stop for essential stuff before getting home, started fine and then my dash lit up like a f&$&?!g crimbo tree, it made it home ok, but then died, i.e. Put key in ignition and nothing happened, nada... So bright and early today got my voltmeter out and went probing... Battery read 0.01 volts, so removed it, gave it a rapid charge and a load teat, it said weak, so after a $180 trip to autozone, I thought I was up and running, more fool me!!... We had dashboard lights on again after 35 mins of running.... So wtf... Is it the alternator????... I would appreciate any help in sorting this out.... Thanks

 

Hmmm....what kind of battery did you buy at Autozone? I got sick of dicking around with batteries and finally got an AGM battery by Deka. That said, a new battery should be plug 'n play and I'd try a hard reset. In a nutshell just connect the + and - terminals together (you'll need a length of wire) for about 2 minutes. If you want the unabridged version you'll have to search on it.

I doubt it's the alternator. I think you're on the right track with the battery but doing the hard reset will clear any latched faults.

 

They didn't have an agm so I got a duralast gold, or I would have got one, lessened learned from my old XK8 jag, my concern is the massive voltage drop on the new battery and I got in to the on board diagnostics and it saying the system is running at 10 volts... And thank you for helping the FNG!!!

 

This sounds like a classic alternator failure. The truck runs fine on the reserve capacity of the battery until it drops to a certain point then everything goes haywire until it dies totally. Did you put a meter on it with the engine running to see if the alternator is charging? That’s the obvious and easiest thing to do. You should see approx 14v with the engine running. Due to the funky load sensing regulators on these trucks it could be anything from 13.5 to 14.5v, but the basic take away is you need to see more than battery voltage.

As for AGM vs flooded, I do prefer (and run) AGM but don’t consider it a ‘must have’ just to keep the truck alive. That’s more of an upgrade for heavier loads like a fridge, winch, extra lighting, etc.

If you saw less than a volt on your battery, it’s gone – chances of bringing it back from that state, particularly with a ‘fast charge’ are very slim. So don’t feel like you wasted money buying a battery. But you still need to verify the alternator output or you’ll destroy the new battery in short order as well.

With the truck idling, put a meter on the battery and report back to us what you see. Until you do that everything else is just guessing.

 

Also when it's idling and you are testing if the results are not conclusive turn on all the electrical accessories possible: headlights, seat/window heaters, radio, etc.

But with your symptoms it should show without that. Good luck. Alternator replacement is pretty easy job.

 

Pulling the alt tonight, getting one on order asap, thanks for all the help

 

While my best guess is alternator, I'd hate to see you waste time and money. I'm hoping you did some basic testing prior to diving into it so you know you're going the right direction.

Just trying to save you any unneeded further headache.

 

IMO its either the alt or some insane parasitic draw, like was stated they are super easy to change, make sure it has a lifetime warranty cause you will change it again

 

Ok new alt installed, yes I got the lifetime warranty!.. Runs great, thanks to all once agin

 

What's the voltage at idle at battery?