True or False: Battery install

[JHT67]

While installing a battery the terminals spark, therefore you have something hot in your electrical system, causing your battery to go dead.

[kingsolver72]

Yes, if I understand what you are saying. Short or "hot" or something is on.

[LockDoc]

Originally Posted by JHT67

While installing a battery the terminals spark, therefore you have something hot in your electrical system, causing your battery to go dead.

That would be true, but it could be an accessory that was inadvertently left on also. Off the top of my head I can't remember if the key has to be on for the radio to operate or not but if it was on but not working could possibly drain the battery.

You might start by unscrewing the small bolt and unplugging the main firewall connector on the engine side and disconnect it. If you did not get a spark then I think it would have to be in the interior wiring. If it appears to be interior I would unplug interior connectors one at a time and test for spark each time until you find the source of the problem. If I am flawed in my thinking I hope someone will chime in and correct me or add to the info.

LockDoc

[Ol Blue K20]

Some current draws I have found more than once dome light on bad headlight switch or door switch, cig lighter shorted out. The way I diagnosis is remove battery ground and put a test light between the battery and the cable if you have a draw it will glow. The brighter it glows the stronger the draw. Next start removing fuses until it shuts off, then check everything on that circuit.. Hope this helps

[JHT67]

Thanks for the advice, sounds like I got some work to do. Here's some background if it might help at all: my wife's 07' Envoy, The power window regulator got all chewed up and the wire broke; while I was working on it, I killed the battery, I don't remember if I had anything on, but obviously the door was open, but either way the battery went dead, so I jumped it, and she drove it like this for a while with it slow starting and a few times dying on her and me having to give it a jump, until finally nothing. Now it sat for about 2 weeks waiting for battery money so today I get a new battery and while connecting the cables, both sides sparked when I put them on. Just thinking about an electrical problem in a newer vehicle freaks me out. Also not long ago the gas gauge quit working and shortly after we got a recall notice, any thoughts that they could be related.

[Ol Blue K20]

Anything is possible you won't until you find it I'm afraid

[Restrorob]

JHT, Any computer controlled vehicle has a continuous draw from the ECU and if applies the stereo clock. The idea is to put a multimeter between the positive battery post and cable, Measure the amount of draw then look up the allowable draw for your vehicle.

If the draw is considerably higher start with disconnecting the alternator, I've seen more than a couple short out.....

[prairewolf]

... site member 68C-15 told me that if key is left in ignition, the computer stays on/active and keeps drawing power. ... something like that. ... we always pull key overnight. ...07 Denali. ... not sure if that helps you but it makes sense to me.

[LONGHAIR]

Ok, hopefully before someone gets hurt, I will type this out again.
Battery safety 101

Never disconnect the positive (+) side of the battery first.
There are 2 reasons for this, most important is the spark factor. Lead-acid automotive batteries give off hydrogen sulfide gas, a single spark can cause a serious explosion. This is also at least part of the reason that battery trays and the surrounding area corrode.
The second reason is that the entire electrical system is still grounded, meaning that the wrench that you loosen the positive terminal with is "hot". If the wrench touches the radiator support while still on the terminal? Direct short....ugly.

So how do you safely disconnect the battery?
Simple, remove the ground (-) wire from the frame, block, head, wherever it is attached. This moves any potential for sparking away from the battery itself. You can't eliminate the spark, just control where it happens. So once the ground is removed you are "safe" to go ahead with any other repairs, including removing the battery itself.
Re-installing goes in reverse....re-connect the ground to the frame last.

[piecesparts]

Depends on what age of vehicle that you are installing the battery into. A lot of the newer vehicles have active circuits that maintain memories and other such items in them, so there is a possibility of a spark. If you left the door open, then of course it could be the dome light circuit. Do you have an alarm system in the vehicle? Things to think about.

[prairewolf]

... And I know Alternators of today are better than the old ones, but, if a vehicle just gets a jump when battery is dead, the alternator does Not do a good job of charging battery... Alternators more or less still just Maintain what is in battery, not charge it. ...to a degree they may charge battery some, but not full charge. ... Your one post said that you jumped it and it worked for awhile starting slower as time went. ... with everything that is powered in a newer vehicle the alternator more or less just keeps up with that too. ...Charge the battery Really good once. ... it won't hurt. ... my .02 thought on it.

[brad_man_72]

If you don't have a multimeter you can disconnect the battery and place a battery charger with an amp gage in its place.
I usually start by pulling the fuse for the radio/clock, then disonect power to computer (things that should all draw power with the key off)
Then check individual circuits starting as close to the battery as possible. Alternator, engine, cabin then move to a fuse box on that circuit, find the fuse with the draw, then find the component powered by that fuse with the draw.

It doesn't hurt to have the battery tested a few hours after its been off of the charger.

[68C15]

you had door open which kept the modules in car "awake". Anything not at rest on late model GM will keep the whole car "awake" and run the battery dead in a very short time. Leaving even a map light on will do this. Depending on year-make-model-options it can take anywhere from 5-45 minutes for the car to go "asleep" after all it's "wake-up" inputs shut off.

when you hook up a battery, you are sending the car a "wake-up" command.

what I do when working on a car and need the door open is latch the door using a screwdriver. Assuming the car doesn't have a door jamb switch this will let it go "asleep".

checking for parasitic drains can be tricky on modern cars. if you disconnect the battery and hook up your meter you have just woke up the car and will have to wait for it to go asleep. I install a jump battery to a constant power source (cigar lighter port) and then disconnect battery. You can also prevent further wake-up commands by not pulling fuses. Instead use a voltmeter and check fuses for any voltage (20 mV for example). To use this method you test from positive terminal to fuses just like doing a voltage drop test. You have all the doors open and latched before test, right?

if you ever do a parasitic test on a Ford product you will spend all day unless you make absolutely sure all the wake-ups are turned off (don't forget that each door has 2 switches)