We're heading out with the trailer in 3 hours, I go out to start the truck this morning and it's turning over extremely slow, no way it will start. I hooked up the minivan to the pass battery and no difference, didn't expect it to make a difference, just had to try.

The batteries were purchased from Autozone (Golds) in 12/08 (sticker on batteries) but i can't find the receipt. Even if I could I think they're going to want to charge them first to test them and we don't have the time. I doubt both batteries could have crapped out but one could drag the other down. They measure around 10 1/2 volts with the key off and after a few start attempts. Key on they're around 6 volts.

Is there a big difference in where I buy them from, AZ or Walmart? I know there are only a few battery manufacturers out there but Walmart may not always have the best.

I drove the truck last five days ago. No lights were left on or accessories plugged in. The only change I've made was add a single Din Alpine deck(5 days ago) but I used the Scosche adapter plug so nothing really changed. No amps or cameras either. The orange memory wire shouldn't draw much at all right, it's just for the presets. Any ideas? I feel like I'm going to have to bite the bullet and buy two new batteries.

 

U can try disconnecting the cables from both batteries and let them sit for at least 10 minutes. Meter them both seperatly when u disconnect the cables, and then after 10 minutes or so. Compare the voltages. If one is bad it will probably be way lower voltage than the other.

 

Have disconnected the cable from one battery to isolate it from the other? I usually remove the ground cable from the driver's side battey to test them individually. I just posted in another thread about a similar occurrence. You may want to see which battery is weakest and try jumping it off from that side. Sometimes this will aid in getting enough current to start and then test the charging system too.

 

Thanks guys, I go do it now.

 

The memory draws almost no amperage...it is not the problem unless it has shorted to ground somehow (chafed). I'd just buy two batteries and get on with the trip and I would buy it from Walmart before Autozone. Why? Walmarts are in rural towns, as well as in cities...I frequent rural America . The second reason is you don't want your trip to be messed up with a later battery problem.

 

IF you got them from Autozone, you dont need the receipt. The batteries are stored in there warranty dept. all you need to give them is your phone number. when you bought them, they required a phone number for warranty issues such as this.

 

Cables unhooked, the Dr. batt showed 11.7 volts and the pass. batt showed 10.6 volts. My smart wife suggested I try the RV's Interstate. I pulled the 10.6 battery and swapped it with the smaller Interstate and the truck fired right up. I then hooked up the meter while running and got 11.7 volts. Looks like an alternator R&R before the trip doesn't it? It should be 14 volts or so right? What about the 10.6 battery?

 

$190 for a 100% new alt from AZ, Alternator | 2000 Ford Excursion 4WD 8 Cylinders F 7.3L Turbo Diesel | AutoZone.com. I wonder if they'll swap out the 10.6 battery?

 

The 10.6 battery may have a dead cell, you can warranty it (by me they just load test it) I wouldn't but your new alternator at the same time if u can. Less chance they will blame your alternator and not want to warranty the battery.

 

I had just called for an alt and explained the situation, they said they would just swap out the 10.6 batt. I think they can't blame the alt as both batteries would be down in voltage.

New finding- I just went out and turn the truck around to face the garage and check the running voltage again, now it's at 13 volts. ???

 

the easiest and first thing you need to do is the wiggle test. wiggle the wires behind the alternator and see if they have a crappy connection.
the jump in voltage which is a good thing but now a scary thing could simply just be a jump in your voltage because your alternator is charging up the batteries. It couldnt charge up the bad battery so it only showed 10.6. now you have good batteries and its doing what its suppose to

 

Mike, my batts were turning the truck over slower than normal too. The dates on mine were 10/8. Walmart batts. Passinger side failed draw ck and they gave me two new ones because they understood ya just can't swap out the one. Truck turns over like a champ. Good luck.

 

The alternator's apparent output will be down around 12 volts when the glow plugs are still on, so any charging voltage measurements must be taken at least two minutes after an engine start.

A fully-charged battery that has had its "float charge" removed (sat overnight or whatever) should be 12.6 volts, NOT 11.7, so both your batteries are discharged, just to different levels.

The alternator Set Point is 14.4 - 14.7 volts, so that's about what you should see after two minutes. If you don't have that, your alternator is suspect.

Pop

 

If it has been idling this whole time it charged your batteries to 13. I wouldn't buy an alternator, just two batteries. Bad batteries are hard on alternators. I'd never replace just one battery - always both.

 

Doesn't sound like your Alt is the problem . You shoud really change both your batteries at the same time because the old one will draw down the new one to be the same . I'd definatley try and charge the battery that was 11.7 up and then throw in new one to match . Then be done with it and HAVE A NICE WEEKEND !