deezel

Hello new to forum.

I will go ahead and start with the dreaded intermittent problem.

I have a 2002 f150 Supercrew 5.4L V8 w/ 88,000 miles.

Over the past 9 months several incidents intermittently occured where the vehicle would not start due to low battery. After jumping the vehicle on 3 seperate occurances the battery checked good by a AAA driver, sears (where batt was purchased) and Autozone. On one occasion the door locks were fluttering and the batt showed 9.3 volts.

Finally gave it to ford and they decided it was a bad battery after having the truck for 5 days.

One week after getting the truck back from ford the incidents recurred but the not the exact symptoms. Now 1st incident the starter will grind slowly and stop with the ignition in the start position. We will let sit retry, same thing. Then retry a third time and it will start normally. Second incident same as first but after starting the engine ran very low idle rough and stalled. Then started normally on 4th attempt. Last one same as first but wife fed up and abandoned vehicle and took my truck after 2nd attempt. About an hour afterward I finally am able to check out and the batt is normal and fires right up.


Any thoughts??


Thanks in advance.

Art

R.S.LOGAN

Could be a " lazy " starter dragging the battery down ? Checked alternator output also ?

deezel

Yes, checked alt and was good. Puts aout 13.7 volts each time I have checked it.

I also checked w/ ammeter for a draw and have not found one yet.

Not sure what you mean by a "lazy" starter. I have noticed no difference in the sound of the starter since we have owned the vehicle. This last incident i checked the voltage after the truck would not fire and it was 12.45.

Art

CatSkinner

13.7 is a little on the low side, but still workable, also, it doesn't come in to play until after the engine is started. It's all battery on the start, and I'd say that you've ruled that out. I think what RS is referring to is a starter motor dragging either due to a dying motor or sticky bearings. Unless you have a coil pack dragging down the system (which can cause a lower output from the alternator), I'd start looking at the starter. Does the 02 have a coil for each cylinder? I can't remember when that started.

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Bluegrass

Here is a little 101 on power.
The battery voltage running and in charged state will be close to 14.5 in these trucks.
You need to monitor the battey voltage at start/cranking to see what is happening.
At an auto store get an LED system monitor 'stick'.
It will have test prods so cut them off and put a cigar lighter plug on so you can plug into the dash socket.
Watch the Leds to see what lights.
If the voltage goes below 10 you have a big issue with either the battery, the cables or connections at some point.
After starting, the voltage should go to 15+ and shows the alternator is replacing the battery charge. If not the alternator/circuit is in trouble.
As the charge is returned, the voltage will drop down to the running level.
This makes it easy to see what you have and where to look for issues.
All for about $15 and use it on any vehichle the same way.
Good luck.