Dead battery

pilot4life · Jun 2, 2012

Anyone ever had their truck go completely dead after 2 weeks of sitting? I left my cell phone charger plugged in for that time but I can't see that killing it. I have a new alt and new batteries and no appreciable draw or an intermittent draw. I had this problem before and it turned out to be the alternator drawing the power...I had it replaced and now 2 months later this pops up again but I am not sure if leaving it sit for so long did it.

Snake · Jun 3, 2012

Its possible, and I hate to say you may have the same problem you had before with the alternator. Some people tried to save some money by purchasing "cheap" alternators from NAPA or other similar places and have ended up with new alternators that were bad.

If you have new batteries and a new alternator that are working correctly, the cell phone charger should not have killed the truck in 2 weeks.

Arisley · Jun 3, 2012

My truck hasn't sat for two weeks in a long, long time. I had a beater for a while and my truck sat for a year once, fired up after 10 seconds of cranking. And that is with a cheapo O'Reilly's rebuilt alternator on it. That alternator has been on there for over 150K miles now. The cheapo O'Reilly's water pump only lasted 120K miles though.

abbottfarms · Jun 3, 2012

My 01 just sat for almost 2 months, just fired it up last Thursday for the first time in that 2 month period, and it was showing good charge on the battery's when I turned the key on. I also had a phone charger in the power plug.

pilot4life · Jun 7, 2012

What is a normal amount of draw on the electrical when the vehicle is sitting? Mine is showing .17A when everything is off...is that normal?

pilot4life · Jun 7, 2012

Looks like it maybe a bad alternator again...shows a .8A draw then when I disconnect the charging cable from the alternator it drops to around .13A.

Is a .13A draw about normal?

Arisley · Jun 7, 2012

Hard to say unless we know what accessories you have.

woodduck97 · Jun 7, 2012

It doesnt have to be the alltenator guys. My friend with 2000 had the same problem. Batteries would go dead after about 2 weeks of sitting. My dad told him that it possibly can be your positive battery cable causing the slow draw because the corroison that get in them after old age. Replaced it with a new ford cable has not had a problem since. Still has the same 2 year old batteies and napa altenator and full sound system. Also he noticed faster starts after the replacements too.

pilot4life · Jun 7, 2012

I have a warn winch hooked to a wireless controller pulls .03A

I have a stereo system that pulls .02A

The batteries are new Diehard Platinums. The cables don't show high resistance, there terminals are clean and tight.

When the Alt charge cable is disconnected the draw drops by .6Amps down to .08A-.13A

woodduck97 · Jun 7, 2012

Sounds like it is the altenator then. But to confirm I would leave the altenator unplugged while the truck sits just to rule it out.

pilot4life · Jun 7, 2012

Already swapped back in my old stock one. I had a bigger aftermarket unit in there. Time will tell

TARM · Jun 10, 2012

One thing you will learn very fast if you have a gremlin electrcial issue is that there is NOTHING Clear and easy or straightforward about tracking down the issue. You have to do it thru the process of elimination and studying the symptoms carefully. Not just the obvious ones. IT can suck but the methodical approach is what end up find the issues most times.

First things are to do a careful visual inspection or the major connections ground and postive. Then whip out the multimeter and get to work. Check the draws the alts ouputs, batteries etc... Hopefully that will get you a lead to follow.

pilot4life · Jun 11, 2012

Ok heres more info. The green/red wire that connects to the regulator never drops to 0v. After I shut down the truck that wire continues to stay at .4v. Does anyone have ideas or a wiring diagram so I can figure out why its showing a slight voltage?

pilot4life · Jun 11, 2012

Found it. I have one of those aftermarket blue blinking lights that turns on when you turn off the ignition. Well after 7 years something went bad in it and it began back feeding into the key on ignition circuit. It allowed enough current through that circuit that when you turned off the truck the wire that feeds the regulator would stay at .4V allowing it to stay on draining the batteries through the charge wire.

Hope this is the end of it.

Arisley · Jun 11, 2012

That's one of the ways that LED's can die. Usually they just become an open (like a broken wire), but occasionally they will short, if they get enough current, a short will become an open.

Glad you found it.