1997 Neon Battery Drain

I bought a 97 Neon from a local dealer 6 weeks ago and had a CD/radio
put in the dash. The problem is that the battery drains if left over
night. The dealer can't find the problem and the local "auto electric"
shop put it on a machine to monitor any drain and said the lights in
the radio were flashing after sitting for an hour. I changed the radio
back to a factory unit yesterday and this morning the battery was dead
as a door nail. Can anyone help??

 

Measure the drain current using an ammeter. The amount of flow may give you
some idea of how it is being drained. Then start looking at the simple
things like trunk and interior lights. If still can't find it, pull fuses
one at a time to isolate the circuit that is causing the drain. Then take
it back to the dealer and point them to the right circuit so they can find
the problem. Keep in mind that it might be a pinched or frayed wiring
harness as well. Does everything electrical currently work properly?

Bob

 

The "electric shop" measured the drain and it was within limits. After
an hour of watching the car the radio light began flashing and the
meter showed the drain like it was bounging up and down. As I stated, I
replaced the after market radio with a factory unit yesterday and still
have a dead battery this morning.

 

Other than having to jump start the car everything seems to work great.

 

Check the battery. If the voltage is below the minimum threshold, then all
kinds of funny things can happen with a computer controlled car. You may
even want to remove the negative battery post and see if it is still dead
the next Am.

Bob

 

Has anyone suggested the obvious - a new battery??? Check the old one
with a MidTronics transconductance tester - should be standard
equipment at any well equipped auto-electric shop.

 

Oh yea...I did have a new battery installed.

 

the parasitic draw spec is .35 of a volt
any more than that and you have a dead battery
by the way look at the top of the battery and make sure it's clean and dry

if there is any acid connecting the 2 posts completeing the circut you
have a draw

 

Before or after the problem began?

 

Draw is not measured in volts, but in anps and milliamps. If you put a
voltmeter in line and use it for an ammeter, the actual value measured
is a pretty worthless number, as the sensitivity of the voltmeter is
not specified. A low sensitivity (say 500 ohms per volt) meter will
read a lot lower than a high sensitivity (say 500,000 ohms per volt)
meter.

Now, how much draw DOES it take to kill a good battery? Depends on the
capacity of the battery, but a typical 500cca battery might also have
a 90 amp hour 20 hour rate. If so, to kill the battery (down to 9.6
volts) in 20 hours would require a constant draw of something like 4.5
amps. In 10 hours it would take something close to 9 amps. I have left
the radio running (accidentally) for a whole long weekend (thursday
night to Monday night) and still had enough power left to start the
old SL6 Valiant with a several year old battery - so if this battery
is going dead overnight from a parasitic draw, it should not be a hard
one to find!!

 

I had a very simular issue with my 95 Neon.
Here are a few things to look at and or try.
Remove the trunk light. (I do not know how, but that was an issue with
my 95 Neon, even though it was setup the same way my 2001 Neon was)
Being as the first generation Neons where very bad for the battery
getting corosion, check,clean and or change the following;battery
terminals, wire leading from Positive terminal to relay box.
Being that this sounds like it started after the new sterio was
installed, check the wiring to the new/old head unit. Did they use a
wiring kit, or cut the leads? You may want to disconnect the Sterio,
and allow to sit over night to see if it kills the battery. ( removing
the sterio Fuse will not be enough as the headlights are also connected
the the factory sterio.)
Let me know if the above works or not.

Mike mlawrenc(at)gmail.com