My batt goes dead over nite?? HELP

[oldhotrod]

I disc neg cable, checked voltage from neg cable to neg post on batt read 10 volts ,should read 1 or 2 volts. I removed the fuse one at a tine (door was closed)Didnt help.I unpluged brake motor no good.I unpluged radio ant no good Unpluged every thing one at a time no good.What else can i do HELP jerry

 

[mikestertwo]

I disc neg cable, checked voltage from neg cable to neg post on batt read 10 volts ,should read 1 or 2 volts. I removed the fuse one at a tine (door was closed)Didnt help.I unpluged brake motor no good.I unpluged radio ant no good Unpluged every thing one at a time no good.What else can i do HELP jerry

You should be reading current, not voltage.

 

[markboss]

Check your clock on the radio, is it on when the key is off?

 

[oldhotrod]

help me with this current reading. how do i read current,and what should it read?

 

[davidf]

How old is the batt? Could be a dead cell if it has some age on it. Winter can be an SOB on older batteries. Try disconnecting it overnight and see how it does in the morn. If it's a dead cell, once started it can work fine all day but will die overnight.

 

[Audie1]

How old is the batt? Could be a dead cell if it has some age on it. Winter can be an SOB on older batteries. Try disconnecting it overnight and see how it does in the morn. If it's a dead cell, once started it can work fine all day but will die overnight.

+1......if the battery has been drained a few times it is a good chance that the battery is toast. If the battery is charged up (12.5 v), turn your lights on (car not running) for about 2 or 3 minutes. Recheck voltage, if it is 10v or less battery is junk. You can also take the vehicle to Advance or Autozone and have them load test it for you. If the battery checks good unhook neg cable and hook a 12v test light between cable and battery. If the test light lights then you have a short in your system. Remove your accessory fuses one at a time, when the test light goes out you will know which general area the short is coming from. Normally you will have something grounding out. There are other ways to find the short, this was the easiest to explain.....hope this helps.

 

[Timbuick]

I had/have this problem on a Mercedes I own, it does work, I was able to isolate which circuit was leaking and it was connected to the alarm/immobiliser.

 

[oldhotrod]

Thanks Audie. The batt is 6 days old but i still had it checked, its good I didnt use a lite but i did use a volt meter on every fuse ,had voltage on all fuses+ all the other plugs that i unpluged one at a time
jerry

 

[bad V6]

Take the negative battery cable loose and place the test light inline between the negative cable end and the negative post on the battery. With a drain on the battery, the test light will burn. Start removing the fuses again until you find the fuse that when removed the test light goes out. That is the circuit that will need to be traced to verify where the short is located.

 

[NASSTY]

Check the fan delay relay.When it goes bad it can drain the battery.

 

[charlief1]

Take the negative battery cable loose and place the test light inline between the negative cable end and the negative post on the battery. With a drain on the battery, the test light will burn. Start removing the fuses again until you find the fuse that when removed the test light goes out. That is the circuit that will need to be traced to verify where the short is located.

AND WE HAVE A WINNER! This is a good start but you need to be in the dark to see if the light comes on. You may have a drain that will barely light up the test light. I've had them barely glow so the darker the better for the first test.:biggrin:

 

[disco stu]

Or just put your DVOM on the 10 mA setting and read the actual draw. You might have to switch the + lead on the DVOM depending on what you have.


Another common drain on these is the factory security (if equipped).

 

[Audie1]

AND WE HAVE A WINNER! This is a good start but you need to be in the dark to see if the light comes on. You may have a drain that will barely light up the test light. I've had them barely glow so the darker the better for the first test.:biggrin:

Guess that you did not read my first post.

 

[TURBOPOWERED68]

i have had very bad luck with Autozone Bats and Advance Bats. i would never buy one again.

 

[Audie1]

i have had very bad luck with Autozone Bats and Advance Bats. i would never buy one again.

That's where I bought my Optima at..........no problems with it. But that being said, I usually only buy AC Delco parts for my TR and not either of the before mentioned establishment's Chinese parts............but that is just me.

 

[turnchaser]

Is your alternator charging? That could be an issue too. Does the batt light light up with the key on engine off?

 

[Tom Walker]

There's always that dredded power antenna. Mine was draining the batt overnite, too. Unplugged it and it hasn't died since.

 

[berserker6]

There's always that dredded power antenna. Mine was draining the batt overnite, too. Unplugged it and it hasn't died since.

same problem. thanks, hadnt thought of my antenna. gonna try that tonight

 

[Waco84GN]

Could be alternator causing drain

I worked on a guys 87 turbo t a few months ago and he had an alternator that had the field shorted to ground and it was actually keeping the field energized anytime he had the battery hooked up. This was easily determined though. Without the car being ran for sometime, but the battery hooked up; the alternator will be warm - hottish to the touch due to the big winding of wire inside being electrified. Kinda like a balled up electric blanket. I did the test light test on the negative cable at the battery, and it had a full blown as bright a light as can be. Unhooked the wire from the charge post on the back side of the alternator and the light barely lit due to his alarm and radio clock.

Just my .02 probably worth a check because this guys alternator was working fine one week and the next week it was chewing through batteries.

Jerry Jr.

 

[Bryan Marietta]

+1 on the antenna. I had to put mine on the charger last night because of it. All seems OK after I put it back in today (unplugged the antenna first of course).