Dead battery

[Hemling]

Hey guys I know this isn't necessarily an auto diagnosis site, but I just experienced a problem with my Excursion. Last few times starting it it seemed a little slow, after the last time the ABS light came on and a few minutes later I lost dash gauges/lights and it barely limped into the driveway. Got the clicking sound of a dead battery when I tried to restart. I was able to jump it, it fired right up and I parked it, about 10 seconds of running it started sputtering and it died. Seems like a pretty open and shut battery, but why the ABS light and it seemed to run really rich when it was dying (kind of like my old race-set up carved big block does all the time). Is there something else I should be investigating?

[_40Fan]

Had an '06 F250 with a 5.4 in today. No dash warnings, but the same story as the OP. Bad alternator in this case.

[Hemling]

I've got a 2002. it has a tach. it does not have a volt/amp gauge though. Maybe that's what it's for. In fact, during the time when my alternator wasn't functioning at all and my battery was slowly dying, no on board light, gauge or diagnostic at all decided that was useful information that I might want.

[Cameo_Phil]

3rd wire may be for the RPM gage if you have one.

[K-9_HANDLER]

Your replacement may come with three and you can use the part. But you only need to use two wires. What year is your ex?

[Hemling]

The alternator connector has 3 pins but only 2 wires going to it. Should I get a replacement with 2 or 3 wires? What's the 3rd wire for?

[Hemling]

update - the three wire connector on the back of the alternator was broken. Hope I can get a new pigtail but at least not an alternator and/or battery.

[SoCalDesertRid1]

2003silverado wrote:
My guess is a bad alternator.

I agree.

[BenK]

All things have an operating range...temp...RPM...altitude...humidity...etc

Electrical/electronic also has an operating range. There is a min voltage to a maximum voltage. Also there is a specification on other aspects of the voltage/current...more so for signal level for computers. Things like voltage spikes that in the pre-computers would not have been an issue...

So, the dead battery may be a victim of the real cause, which IMHO, suspect the alternator...but that could also be the voltage regulator(s) too

Be careful of just changing out parts...and...running the new part for a while...the culprit could still be there...to take down the new part(s)...chasing the tail so to speak...

Your comment of ABS and injector funniness is indicative of this. Both the cause and the possibility of it taking out other components and/or systems

[Hemling]

it does sound like the charging system is suspect, I'll be checking both out tomorrow. I'm just confused that no warning lights came on during this time. Both battery and alternator are less than 6 months old, so we'll see.

[2003silverado]

My guess is a bad alternator.

[K-9_HANDLER]

ABS can come on with bad battery. It will usually reset on its own after new battery is installed with in a few miles. Id get both the battery and alternator tested.