So here is the deal. I went on a slight vacation (deployment to Iraq!!!!) and during that time I let a friend barrow my truck on and off. He never had it more than a day and it was only a couple of times. Most recently to get it washed and fueled up for when I got home.

I got home went out and it started right up. Not a hitch at all. Then the next day I went out and it would turnover once and then the starter solenoid would click. So I jumped it off and everything was fine. The next time I went to start it would crank faster but I still needed a jump and after letting it idle for an hour I was able to go out and start it on its own.

I let it sit over night and tried to start it today and the battery wouldn't even crank it. So I pulled the batter put it on a charger and got it load tested. IT passed like it should have. It was new 8 months ago.

I know the alternator is putting out because the more I ran my truck the easier it was to start it and while it’s running everything is normal.

So im down to something is draining the battery unless anyone else has another idea.

Anyone knows of any common things that drain on f150s. I know about the door light sensor and I sprayed it with triflow.

What you guys think.

 

Glad you're back, twintips! Thanks from all of us for being the "pointy end of the spear".

Do you have a voltmeter? I'd like to know what the voltage is on your battery, both after it's "sat" a while (with the engine off and nothing else on like interior lights) and when the engine is running. An unloaded battery voltage in the 12.6V range is about right. When it's being charged by the alternator, you should see 13.8-14.2V I think.

If you see these readings, I think you have battery cable connection problems. Possibly at the battery terminals but I'd suspect corroded grounding cable connections on the frame or motor block more (they're exposed to all kinds of dirt and crud).

It probably works ok after being warmed up because the electrical connections improve with heat and vibration.

But, if the alternator voltage is low (the only valid test), you have a bad alternator.

Can you do these tests?

- Jack

 

I didn't have volt meter handy but i did a load test on it and it past. The alternator is brand new. Less than 5000 miles on it. THe conections were good. I put brand new terminals on it right before i left. I will be putting hte battery back into it in the morning and will hit it with a volt meter just to double check.

 

New doesn't always mean good. The Bradley was new. The Hummer was new. A while back, the F-111 was new. Lot's of our brothers died in those "new" machines.

Voltmeters don't lie.

But, there's a guy going by the name of SSCULLY on this forum that is much better at figuring out these problems than me. Maybe he'll chime in. I'm just giving you my approach if I had your problem.

- Jack

 

So i put the fully charged battery back into the truck and went to drive it to the shop where i can dig more into it and post voltages and ti wouldn't crank. It would click then crank for a second and click some more.

So i went a step further and crawled under to look at hte starter and the conections are horrible. I have to pull the strarter to pull the tranny which is what i am doing now so i will post more to follow soon hopefully.

I hope thats the problem

 

Thanks for the help to our fellow traveler, Jack. Thanks to you Twintips for keeping us safe and free here at home. our son is an Apache pilot so we have a special place in our heart for those that make the sacrifice that you have.
And thanks Jack for always giving help that "you can take to the bank". It's always encouraging when those that come for help really get it! Roger

 

Apache pilot! Talk about being at the "pointy end"!

Thanks for your kind words, Roger. But as I said, I just "vocalize" what I would do in his position. It DOES begin to sound like I could have been right for once, doesn't it? :o I keep trying to gather "Atta Boys" to make up for the "Aw Sh*ts". (But, as I learned in the Air Force, one "Aw Sh*t" is worth 1000 "Atta Boys".

- Jack

 

Isn't that the truth!!!!!

 

did you get it fixed? corroded wires at the starter could be the problem!

 

I did all my work over the last two days. Dropped the transmission, replaced the rear main seal, dropped the front diff, and replaced the cv axles. I was putting it all together today and found one more issue so i never got to even try starting it. And im bummed cuase its just sitting there with one wheel off and thats it.

HOpefully the place where i was working on it opens back up on wednesday and i can go in there and fix the little issue with the spindle and start it right up.

I was wondering about batterys. I got to thinking. Could a battery pass a load test right off a charger but still be lossing voltage over time???

I was going to throw the voltmeter on my battery today and check it but i got hung up.

 

Yes I had a Optima that would pass all load tests but when you let sit over night disconnected from truck and charger voltages drops to 12.3v. A healthy battery reads 12.6v.

 

But a battery atr 12.3 would still start a truck.

Mine wouldn't turn over at all. Could it lose that much?

 

Yes i had a bad relay in my 07 F150 and it would drain the battery within a week, i would start noticing symptoms of a low battery after 1 or 2 days of sitting. New relay and trucks voltage sits at 12.6v for many many days now.

 

wreed, I don't think you are quite answering twintips' question. From the symptoms he described, his battery is not losing its charge while sitting. It just doesn't start the truck even after being fully charged. But, the relay clicks so some power is getting there, just not enough.

I DO know of ONE case of a battery that measured healthy under no load but as soon as a load was applied, the voltage dropped to near zero. Now to be completely honest here, it was a flashlight battery, but the electrical generating process is pretty much the same.

So, twintips, you COULD have this problem, which is why people will suggest a load test. But, I believe you said your battery did pass a load test.

I'm sticking with my "clean and tighten" all connections recommendation.

- Jack

 

I was taught that when you load test a battery you always do it twice at 1/2 the CCA rating for 15 seconds. ie; if it has a CCA of 800amps you load it with 400amps for 15 seconds while watching the voltage. You have to read the voltage while the load is applied as it will rise once the load is off.
The first time you're just removing the surface charge. Wait one minute after the first test and then do it again for a true reading. At 70*f temp if it falls below 9.7v on the second test it's bad. At colder ambient temps the acceptable voltage drops a bit. It can fall to 9.1 if it's 32*f and still be considered good.
Hope this helps.