my van drains the battery when it is off and just sitting , i have a new battery and new clyone but it wont start just clicks
2007-01-21 06:19:45 · 6 answers · asked by JOYCE D 1 in Cars & Transportation ➔ Maintenance & Repairs
A Bad alternator will drain a battery while it just sits.
That's not ALWAYS the case when an Alternator Goes Bad.
It depends on what part of the alternator fails,,,and how the part fails.
They have some electronic things in them called Diodes.
Their Purpose is to convert the alternator's Alternating Current into DC>Direct Current which is what charges the battery & powers the vehicle.
The diode's FUNCTION is like a One-Way Check Valve.
Electricity will flow through it One Way,but Not the Other.
Diodes can fail OPEN,,which is like a blown fuse.
It wont conduct electricity EITHER way.
No Connection.
Or they can fail CLOSED.,,,which is like a Direct Connection.
And electricity can flow BOTH ways thru it.
When they fail CLOSED and conduct in Both Directions,,,
It No Longer BLOCKS the Battery Voltage from "flowing OUT " of the battery to ground.
So it drains the battery.
Tricky part is that an Alternator can STILL CHARGE with a Failed Diode.
It'll charge enough to Not drain Battery while running.
And enough so that Gauge or Light indicates everything is OK.
Then when you turn engine Off,,,there's still a drain on the battery just as if a Light was stuck on somewhere.
A Diode can fail at any time.
I've seen enough of them BAD right outa the Box on Rebuilt Alternators.
It Happens.
It can be tuff to find sometimes,,,because a DIODE is a "silicon SEMI-CONDUCTOR" device.
It's very definition is like,,,"SLOW LEAK"
When one fails CLOSED,,and shorts to Ground,draining the Battery.....it can easily be Only a Very Small SHORT.
'Cuz it's only "Semi-Conducting" Backwards through a very high resistance.
Acts like a Tiny Light Bulb drawing battery down,,,rather than a massive,direct short
Which accounts for a typical symptom of a Vehicle being able to Drive all day long,,,Start & Stop several times for shopping,errands,,go to lunch,,etc.....and all seems Fine.
Then Next Morning,,,Battery is Dead.
Or,,,Battery holds up for 2~3 DAYS,,,then goes dead.
Jump Start or Charge it,,,It's OK for a few Days then Dead again.
Sloooow leak.
Most Alternator Tests have a hard time finding it.
Easy way is to use an Ohmmeter,,,Disconnect Batt & Alternator.
And check for any continuity(Connection) between Ground & the Alternator's Battery terminal.
Should be ZERO.
Not unusual to find a "Good Alternator" with a Faint Drain back to ground.
Draining Battery is Bad Enough,,,but a Batt in decent general condition will survive with just a good charging.
But a Bad Diode KILLS a Battery.
because it begins "charging" the Battery with ALTERNATING Current to various degrees.
It will ruin even a very good battery eventually.
It's a Different condition than simply Draining it with some sort of Load or Short.
Or just NOT Charging it.
It's more like,,,"attacking" the battery itself with A/C Current
On "Old Vehicles" when Key was Off there was ZERO drain,,,
and it was easy to do a simple Alternator Diode check.
On Newer vehicles,,,there's always a SLIGHT Draw from Radio,Engine Computer,etc.
It takes Month's to drain a battery thru those draws,,,very,very slight.
But however small the "normal drain" is,,
it's still it's enough to require Alternator be UNPLUGGED and totally isolated from vehicle's electrical system.
Then,,,it's BATTERY terminal should test as 100% isolated from Ground.
If it's NOT,,,alternator has a Bad Diode,,,and it WILL drain Battery overnight,,or every couple of days.
And meanwhile,,it's destroying the Battery with A/C.
Get somebody to Disconnect the Alternator's plug-in connection from Van's wiring harness,,,
and Then check it's Battery Terminal for any contact /Drain to GROUND.
Once it's Disconnected,,you can even check it with a small bulb or voltmeter connected Between Battery Post and The Cable.
The Battery's Red/+/ Positive Terminal is POSITIVE,,,
and The CABLE effectively becomes a GROUND,,,cuz it's Back-Flowing to the vehicle's frame thru the Bad Alternator.
It's usually a FAINT connection,,a Hi Resistance Short.
But it's same effect as connecting Both Battery terminals to each other.
Never a good Thing.
If test Bulb lights at all,,,or meter shows any Voltage when connected between Battery Terminal and Battery Cable,,,,
while Alternator is Disconnected from van,,,,
Alternator's bad,,,cuz it's acting like a connection directly to ground.
Just cuz an Alternator appears to be charging,,
dont necessarily mean it's GOOD.
It has TWO Jobs to do.
1)CHARGE,,,,and
2)Block Reverse Current Flow.
If it fails at Either,,,,that's a problem
There's all sorts of OTHER possible Drains.
Your Van doesnt have anything besides maybe Engine Compartment light which is Not easily Visible.
If you had anything "stuck ON",,,even intermittently,,You'd see it.
A genuine SHORT in wiring,,,rarely produces a slow drain overnite-type
An EXCESS Draw thru the few "Always On" devices typical of your van----Radio and ECU/Computer...
that normally would be a Serious Fault in those type devices . You'd PROBABLY have other symptoms besides just Battery Drain.
Something "wouldnt work",,,most Probably.
Other vehicles have a whole ZOO of bugs that can cause slow drains.
Yours is rather simple & straighforward in that respect.
Not much about it will cause a slow drain.
I'd look hard at Alternator,,,Charging well or not.
If it's NOT the alternator,,,then at least you're CERTAIN it's not.
And certain from More Than only a partial Test of only "Half the Job" an alternator is required to do.
Good Luck with it
2007-01-21 08:20:48 · answer #1 · answered by Anonymous · 0⤊ 0⤋
1. are you sure your alternator is charging the battery properly? often times on older vehicles a dead battery will put to much load on the alternator, and while it still works it's not putting out enough amps to properly charge the battery. many chain auto parts stores will test your charging system for free. auto zone, and advanced auto are to guaranteed locations.
2. are your terminals clean, and tight?
even though the new battery has clean posts you need to be sure the terminals on the van are clean to make a good connection. also, if they terminals aren't tight it will cause mild arching, and that will drain the battery.
3. are all your grounds connected?
be sure that the extra ground coming off of the ground terminal is connected, and clean at the body. it doesn't seem like it should matter, but without that ground you won't have proper charging, and it can cause starting problems.
4. if none of this works then you need to start looking for possible sources of shorting or power drain. be sure your door switches are turning the inside lights off. if you have any accessories, CB's, amps, ect... be sure the are all shut off when the vehicle is off, and that they don't have any shorts in the wires causing the power draw.
2007-01-21 06:33:45 · answer #2 · answered by knowitall 3 · 1⤊ 0⤋
Someone with a multimeter can track it down real quick. The voltmeter will tell them if the alternator is OK, and they can put the ammeter in series with the battery cable and see any current draw, then disconnect stuff and pull fuses till it goes away to find the source.
2007-01-21 12:27:36 · answer #3 · answered by Nomadd 7 · 0⤊ 0⤋
better check the alternator.if its shorted out then it will drain the battery.also hows the terminals?are they good ,clean and tight.you said you replaced the solenoid,then make sure the wires are tight and on the right post.
2007-01-21 08:30:29 · answer #4 · answered by Anonymous · 0⤊ 0⤋
u may want to have it checked by a certified mechanic it sounds like a major battery draw in the vehicle could be a open circuit somewhere on the vehicle body
2007-01-21 06:31:29 · answer #5 · answered by nineball_sinker 2 · 0⤊ 1⤋
have u checked the alternator,,,,is it chargin when u have it on ,,,check the voltage when its on ,,,on ur panel
2007-01-21 06:29:50 · answer #6 · answered by virginia l 1 · 0⤊ 0⤋