dead battery
 

ok so i smelled kinda like a burnt smell last night when taking my son to bball practice then i got up this morning and truck cranked once then dead as hell. So embarassingly i had to pull my wifes minivan up and jump truck. I let it run for bout 15 min shut it off went to restart and dead again. So i again jumped it and drove it bout 5 minutes to my parents house and the wrench lite came on and my radio went off and the abs lite came on, so im assuming its the alternator, but now the question is how do i know what alternator to buy idk if its dual alternator or not. Now i have to drive my old mans honda ridgeline and im not liking this so i need get this taken care of soon lol. Its a 2005 f250 6.0l with 156000 miles. only mods is 3inch lift 35s and egr delete.

Pop the hood and look, do you see two alts there? There will be two belts too. Just shooting from the hip my guess would be no. The truck's PCM usually just switches between the two alts, so if one died it should run off the other without issue. Here's what they look like, as I do have dual alts:

Attachment 36440

Attachment 36441

I had almost the same thing. Slow cranking.... Smelled something hot.

The battery on the passenger side had shorted 2 cells and was sucking the other battery to death and getting really hot.
The best the sick battery could do was 8v when disconnected.

Check the voltages with the batteries disconnected. The 2 batteries are just in parallel with no isolator.

alright thanks guys i will check both of them things out. so with the cells dead you didnt need to replace the alternator just the battery or both batteries or both batteries and alternator? lol sorry just trying to be kinda specific i never owned a vehicle with 2 batteries before.

Take the batteries out and have them load tested at Advanced Auto or the likes, they do it for free. That will tell you a lot right there. They can also bench test alternators too...

ok so i have a single alternator i took batteries to napa and they tested them said to dead to test but didnt see any dead cells. is there any certain sized alternator i should get thought maybe since i was going to replace it maybe i should use a bigger one. both batteries are still under warranty one was bought in 09 the other in 10.

---AutoMerged DoublePost---

also just thought bout it where is the pulley tensioner to release the belt and do i need a special tool for this truck?

A breaker bar or 1/2" ratchet works just fine. Hard to point on mine because I have two tensioners and two belts in the way. Just look down in there you should be able to find it pretty easy.

Did they test the alternator? Are you sure you need one? Could just be a dead battery draining everything down. One dead battery will kill the other too...

No i took the batteries out and they was to dead for them to test so im gonna throw them on the charger tonite and take them back tomorow to have tested again. I will let u know the results.

Once good batteries are in truck . check the base battery voltage with engine off. then with lights and all accessory on the voltage at 2000 rpm should be at least 0.2 volts greater then reading when engine was off

ok so i pulled batteries and alternator took it all to advance auto got everything tested my batteries are good alternator is dead, so next step they didnt know what amp the alternator i brought them is so they recomended me getting the 135 amp i guess i just dont trust most sales people unless i know them so im just tryin to figure out what amp i should get cuz there is a pretty significant price diffrence between the diffrent amps. i dont run a plow or anything like that but hey who knows what i will have in the future.