Trying to charge battery acts like dead short...
 

So I went out to start my 99 TB and it's dead as a door-nail. First my key was stuck in the ignition (this is annoyingly stupid)... Anyway, went to hook up the charger, positive first... as I began to touch the negative post, the meter on my charger was jumping all over the place and sort of buzzing. I disconnected immediately. Checked connections and tried again, this time just barely touched the negative post; same thing. How do I trace this down? Oh, At least I did get my key out!

Is it possible that the grounding I recently did on the rear defroster is causing this?

Gotta go help the kids move, we'll look into things later; just wanted to throw this out there and get some preliminary thoughts.

Thanks!

Disconnected old battery and am charging it now; seems to be going fine. Will search threads on diagnosing battery drain... Yipee! Will also look at the recent "fix" on rear defroster. Got a new battery waiting, but hate to stick it in there until I do some checking around... the way the charger initially acted was just too weird!

I saw in another post where Lanny81 asked if either of the battery posts were disconnected before charging.. This is new to me, can someone elaborate on this? I did not do this at first... did I fry something doing this?

https://blazerforum.com/forum/2nd-ge...97/#post644490

Follow up with more questions
 

Battery charged and ready first thing this morning. I put my meter on it and it was 12. something volts, but they were dropping pretty quickly, (still not hooked up to TB). Once reconnected to vehicle I found the 4-ways had been turned on & left on... completely draining the battery. I have no idea how old the battery is, but my meter also allows a load test and it shows the battery as good.

So isn't this a conflicting message- dropping volts unhooked from vehicle and load test shows okay?

The last thing I did was take a reading off the battery vehicle with the off, it was 12. something volts. After starting the vehicle it read 14.something volts. Does this "test" properly indicate the alternator is working?

if the voltage is dropping and the battery is out of the vehicle ... battery is garbage
The battery is just taking a surface charge

the only true way to load test a battery is with an old school carbon pile tester IMO

Chances are dealing with the key stuck in the ignition is when the 4ways got turned on

Thanks for the input. I left the old battery in the vehicle over the weekend, drove the TB several times, and started fine each time. May just keep this new battery on the shelf until it fails me again.
I am curious to hear more about disconnecting a terminal before charging; is this required on TB's?