06 5.4 has factory alarm system, disarmed the truck went to start it and the alarm went off, turned if of tried to start it and "click click". Turned the ignition of and the gauges start buzzing. Cleaned the battery terminals and same thing "click click" followed by the gauges buzzing. Has a newer battery checked with volt meter reads 11.2 at the posts. Any ideas?

 

11.2 is kinda low. I would have the battery checked. Usually they around 12.6 plus/minus a few tenths.

 

Battery voltage should be higher than 11.2, so I would try putting a battery charger on it and see if it will start after a good charge. Even though it is a new battery, it might have gone bad. Or it may have something to do with the alarm thinking that the truck was being stolen, and is not allowing it to start now because of that.

 

Thanks, Ill start w/ the battery and go from there.

 

did you check your fuel pump shutoff switch on the fuse panel? Maybe whatever set off the alarm tripped the shutoff too?

 

11.2 is WAY low. I know the 0.8 seems like it would be close to OK, but it should be closer to 13 volts. You should be able to jump start the vehicle, but go to some place that can test the battery and charging system (like where you got the battery).

 

The symptoms sound exactly like a near dead battery to me. 12 volt batteries as used in vehicles aren't really 12 volts. A fully charged typical 12 volt battery will check out 12.6 VDC or higher.



11.2 is discharged. Maybe you have a steady drain on that new battery or maybe it's defective?

Here is a decent read on batteries and their design and how they vary some in required charge rates just to get you started. It's not the final word however. http://en.wikipedia.org/wiki/Automotive_battery

Here's a downloadable guide in pdf to charging batteries.
http://www.operatingtech.com/lib/pdf...20Charging.pdf

 

It was a defective battery, the new one reads in at 12.8 v . Crappy duralast they just go bad with no warning, still had the warranty got it replaced for free. Thanks for the help.

 

I replace my battery every 2 years... the old batteries I hold on to and use for jump starts and machinery starts, or portable inverters. I've got a nice Schumacher digital 100 amp charger and I've wired them up to all be on standby (trickle) charge.