parasitic drain? 2002 Sierra 1500

[MrMarty51]

currently it has no battery in it since it is completely dead and won't take a charge. it's sitting on my bench until I go to the store.

I would argue my meter is fairly accurate. it shows around 12.3 to 12.7 when testing all my other vehicle batteries when I test the alternator output on my trailblazer and silverado I can watch it hover around 13.5 to 14.0 ish and can see the subtle fluctuations on the display when turning on and off ac or headlights. this alternator however goes right to 14.7 and doesn't budge.

Hook your charger to the battery.
Take a D cell flashlight battery.
Hook jumper cables to the battery terminals.
With the charger turned on, touch the positive car battery post to the positive D cell end, and then the neg car battery jumper to the neg D cell end. Just a touch is all it takes.
I have seen totally dead car batteries that would not take a charge and it takes a sligjt amount of a jolt to excite the car battery into taking a charge.
I was taught this by an old timer mechanic and have used it several times myself.
After the little jolt and battery charged the car battery functioned just fine for many years.
Give it a shot, whats there to loose.

 

[dbrannon79]

Hook your charger to the battery.
Take a D cell flashlight battery.
Hook jumper cables to the battery terminals.
With the charger turned on, touch the positive car battery post to the positive D cell end, and then the neg car battery jumper to the neg D cell end. Just a touch is all it takes.
I have seen totally dead car batteries that would not take a charge and it takes a sligjt amount of a jolt to excite the car battery into taking a charge.
I was taught this by an old timer mechanic and have used it several times myself.
After the little jolt and battery charged the car battery functioned just fine for many years.
Give it a shot, whats there to loose.

I have heard of folks doing this with a DC welder. taking the leads and jolting the battery for a few seconds. 50v dc at 80-100 amps is quite a jolt!! LOL

 

[MrMarty51]

I have heard of folks doing this with a DC welder. taking the leads and jolting the battery for a few seconds. 50v dc at 80-100 amps is quite a jolt!! LOL

I wouldnt be so brave as to attempt that, with a welder.
After jolting the car battery, it still took some time before the charger meter would begin to move.
I would do the jolt procedure only after leaving a suspected good battery on a charger for a long period of time and the battery was not accepting the charge.
I always use an old style analog charger, not one of them new fangled computer jobbers.

 

[WarWagon]

Take a D cell flashlight battery.

I have heard of folks doing this with a DC welder.

Batteries are dangerous. Dad tells me a story of a couple of 8D batteries that blew up in their repair shop in/during Vietnam turning a fellow's face into hamburger.

Lead is toxic and lead shrapnel will give you a lifetime of problems. F*** around and find out!

This is why modern chargers will not turn on if the battery's voltage is too low. the "D" cell tricks the charger to turning on when the battery is overdischarged and/or may have a shorted cell. This was a very dangerous situation, shorted cell charging with a dumb old school charger.

 

[dbrannon79]

I've been fortunate enough to have never been around a battery explosion and hope it stays that way, but have seen what they can do. back when I was turning wrenches on cars for a living working for my wife's uncle, her aunt was driving a dodge minivan. her battery had exploded under the hood and did some serious damage to the hood pushing up on the steel.

 

[trouttrooper]

Update. Won't bore everyone with everything I've tested, including with a neighbor who use to work for GM and still has his Tech 2. It appears that I had an intermittent faulty brake light switch that would sometimes turn on the brake lights if it sat outside in the extreme hot sun all day. It would sit inside my shop for days on end and no problem. Pulled it out to work on another vehicle, and the next day it was dead. This weekend when I put a good battery in, I noticed the brake lights came on. Tapped the pedal a couple times and they went out. Talked to my other neighbor who faces my shop driveway and she said she forgot to tell me she noticed the brake lights were on awhile back at 3am. She thought it was odd I was coming home so late and just sitting in the truck with my foot on the brake, LOL. Replaced the brake switch, and leaving the truck outside with instructions to the neighbor to let me know if she ever sees the brake lights on.

 

[Will L.]

Wow. Glad you found it- what a total pain intermittent electrical things are.
This is one of those things that makes you go “oh yeah, that makes sense”.