95 850 left ignition on WAY too long

farmmedic · Post by **farmmedic** » 01 Feb 2012, 07:12

yesterday i was trying to figure out why the rear wiper on my 1998 850 wagon wasn't working
in the process i had turned the ignition on so i could get power back to the wiper motor
that thing is basically huffed and ultimately not the issue i face now
once i had narrowed down the issue to the fact that the wiper transmission was TOTALLY seized and had burned up the motor, i went on to other things and completely forgot that i had left the ignition on
when i went out 5+ hours later to go somewhere the battery was run down to the point that it wouldn't start the engine
turned over the starter motor, if slowly, but wouldn't catch
this is a new battery (about a week old)
i put the trickle charger on it over night to charge
this morning i went out and it still won't start
all of the fuses are good (checked with voltmeter)
the fuel pump pressurizes the system (i get a good squirt at the fuel rail) and it cranks over though still very slowly
i'm working on it alone so as yet i don't know if i have good spark b/c i can't crank it over and watch at the same time
or do anything that takes 2 people
not yet anyway
and here it the kick
the battery seems to lose most of it's charge after only 15 or 20 seconds
it sounds like it almost wants to catch

what have i done?
cooked the battery?
the starter?
something else?

Post by **jblackburn** » 01 Feb 2012, 07:16

If you run the battery down beyond a certain point, it won't hold a charge anymore.

You can take it back and it will be covered under warranty, though (don't mention that YOU drained it, of course - just say it's not starting anymore).

Have a friend or someone that can jump start you? AAA?

farmmedic · Post by **farmmedic** » 01 Feb 2012, 07:28

maybe after a while on the jump start
the extra icing on the cake is that after i finished off the volvo i was working on my MB 300sd and left the doors open to dry out the inside
also for 5+ hours and killed the battery on that one too
no AAA
just a great day
working on it (the jump)

i don't think i took the battery to a place it can't recharge from tho
the voltmeter says 12.25v
on both batteries actually

Post by **jblackburn** » 01 Feb 2012, 07:31

A fully charged battery should read around 12.8V. 12.25 is low on a charge, but may start. I drained mine down to 11.9 the other day by accident running a tire pump (I didn't know it could kill the battery in 10 minutes) and the starter wouldn't even click. Will the Mercedes start off the battery from the Volvo?

farmmedic · Post by **farmmedic** » 01 Feb 2012, 07:32

i'll give it a shot

farmmedic · Post by **farmmedic** » 01 Feb 2012, 07:37

that's a big no both ways
i'll leave them on the chargers and see if i can find a jump for now
thanks
will advise

turbozutek · Post by **turbozutek** » 01 Feb 2012, 07:38

This is why it's nice to have a manual - even with the most miserable charge left in the battery it'll still start with a bump or push start, or even rolling down a hill!

Chris...

farmmedic · Post by **farmmedic** » 01 Feb 2012, 10:10

apparently my trickle charger just wasn't up to the task
and the full size charger that i thought wasn't working actually is working
and i did finally find someone who could give me that jump start
that's one of the hardest parts of being self employed, everyone else is at work

any way
took a bit of cranking but it did finally start
jumped the Benz off of it and now both are going

note to self
TURN OFF THE DAMN KEY!!!

i do feel a silly
thanks again for all the help

BTW...Chris, ya takes what ya gets, i too wish it was a manual but the price was WAY too good to pass up
maybe my next one will be a manual

Post by **jblackburn** » 01 Feb 2012, 11:10

We've all done silly things like that sometimes. Glad you got them both going

Post by **BEJinFbk** » 01 Feb 2012, 11:25

+1 on a full size charger.
As for the wiper, have you
Got power on both feeds ?
It's not unheard of for the
Wiring harness to fail near
The tailgate hinge.