went to start the truck this morning and nothing. starter turned once and that was it. no juice left. its been under 30 degrees here. Now is it a bad battery or both batteries or the altenator or something worse? When it starts it keeps a charge fine. Drove 6 hours to tow a car yesterday. It just acts like it doesnt have enough juice to keep turning the starter till the truck fires. When i can plug it in it starts fine. Any help? I need to get her running asap!!

 

Have the batteries load tested sounds to me like a battery issue just from what you are describing. And also make sure the battery terminals are clean and tight. How old are the batts, Is there any thing inside that might be causing a current draw on the batts over night ie cell phone charger, dome light staying on things like this, and also after you test your batteries what is the alternator charging at should be anywhere from 13.8v to 14.6v to properly charge the system and use a volt meter to test to see what the alternator is charging at that way you know exact voltages dont go by just the volt gauge in the dash. The volt meter will gibe you a more accurate reading.

 

just checked the batteries with my multimeter. Before the ignition is turned on both read 12.4v. after i turn the ignition on one stays at 12.4 and the other drops to 10.6. I just cleaned all the terminals the other day. cables are good. nothing stays on in the truck. everything is always unplugged or off.

 

Sounds to me then from what your readings are then yes you have atleast one bad battery, if you can would take them out and take em to a auto parts store and have em load tested. Will prob have to replace at least the low one but if you can I would replace both together. That way you know they are both good to go for the winter. Because if you are in CO right now we still have alot of winter left to go with 30* and below temps

 

ok thanks alot for your help. No im still in north carolina but coming home next month on leave. looking forward to the snow! Thanks again. Have a good weekend. Hopefully this will fix it