jbmx4life

I need to know how I would go about testing for a draw on my battery. I have a 1989 Beretta GT and the battery will go dead after sitting for a few days (over the weekend). I leave my radar detector plugged in all the time. I do not know if this is causing it but it hasn't in the past so I am just ASSUMING that it isn't but I also look at it as maybe the culprit. Once I can figure out how to test for a draw I can for sure find out. Please let me know.


Jeremy

jsgold

I cannot tell you exactly how to test the amount of draw, but offer some suggestions. Get the battery tested at any Advance parts store or similar, as they have the correct equipment to check for voltage as well as capacity. How old is the battery? If over 3-4 years it maybe failing. Have you cleaned and inspected the cables? If you have a volt meter, have you tested the voltage while running vs off? Should have over 12 volts when not running, and 13+ when running. If voltage is low when running, say 11-12volts your alternator may be weak. Can get that checked as well at Advance for free. Batteries that are weak will show themselves when the temperature drops. Your car always has some draw for things such as radio memory, computer, etc. If you think the radar detector is at fault, try unhooking it and see what happens. Is there a power switch on it or does plugging it in activate it? Nine times out of ten your battery is just losing its abilty to retain amperage and needs replaced. If you do have a good meter that can measure amperage draw, perhaps someone can advise you further.

jbmx4life

Thank you for your quick response. I for got to put a couple of things in my post that you had pointed out as I wrote this when it was really late and I was tired. The battery is brand new as of this year and the alternator is brand new as of maybe a week or two. Thanks for the help.

Omega_5

Check the trunk light... it's famous for killing batteries... (killed my battery twice b/f i figured it out). The switch likes to stick in the "on" position. To fix it either replace the switch or take out the bulb

jbmx4life

well here is my update....... I have been working on this problem yet and still haven't totally figured it out. I Google'd on how to check for a draw on a car battery and it came back with using a test light between the positive on the battery and the positive cable once the cable is disconnected from the battery. Is this the right way to check this??? If so I thought that it was my lighter socket. I just replaced that and checked again........... still got the same prob with a draw. If I go to the fuse block and pull fuse #11 (Courtesy Lamps, Clock, Doorlocks, Horn, Audible Warning System, Cigar Lighter [Coupe]) then the test light has no illumination so I am guessing it to be somewhere in that circuit of stuffs. Please HELP!!!

hotpants

try disconnecting the negative battery cable. Then take a 12 V. wire tester and touch one end to the neg. post on the battery and the other to the cable. Make sure the doors are closed. If the light glows dim, its probably a regular draw, if it is bright, you have a huge draw coming from somewhere. Then pull each fuse to see where the draw is coming from, as soon as the light goes out you will know where it is coming from. Make sure the doors are closed!