1999 Volvo S70 battery drain
My 20 year old has a 1999 Volvo S70. It has a
brand new battery but was just sitting for a
bit while it waited for other repairs. While it
sat at the garage, the mechanic said the
battery drained and needed to be jumped.
There a clicking noise when you open the
door and a blinking red light on the dash
which appears to be a dummy security
system. The mechanic nor the guys at
Firestone seem to know what it is but the
mechanic (this guy that has his own shop
and works solely on Volvo’s) thought it might
be the reason the brand new battery is
draining.
Any thoughts and is this something we could
disconnect ourselves so it wasn’t drawing on
the battery ?
a battery draining is either a bad battery, poor connection positive or ground or a draw from one of the electrical circuits However it is a piss poor idea to jump a car with a dead battery as it is undercharged potentially has a short in the electrical system and will assuredly burn up the internal voltage regulator inside the alternator. You need to charge the battery and do a voltage draw test to find the problem circuit. After you find the problem circuit and repair it then check to see if the alternator is still putting out between 13 and 14.5 amps with a fully charged good battery.
First thing's first, check connections at the battery. Second, perform a voltage draw test. Lots of info online, basically check current draw at battery positive and pull one fuse at a time and backtrack from there to find the faulty component.
don't use the positive side to do this test as it can be done from the negative side as well safer. Watch this video ........ https://www.youtube.com/watch?v=zdIKNnwEjIs ............. This can also be done with a 12Volt test light just to find the draw while inline and pulling fuses.
Yes, use the negative if possible, I usually prefer to avoid messing with the positive terminal if the negative is connected... it could turn into fireworks real easily.
In the Fuse box description - main fuse box. I changed the Fuse # 7 (50A) and the problem was solved. See the link below to see the anatomy of the main fuse box. https://imgvehicle.com/volvo/s70-v70-i/fuse-box#post393
Sounds like a parasitic draw to me. I would try something a bit more simple using a 12Volt test light only to try and find the shorted circuit. Just disconnect the negative post wire from the battery and connect the test light inline from the negative terminal to the negative cable. If any power is being drawn it will light up. The dome light or fuse should be removed as well as any fuse that normally draws power when the vehicle is not in use such as the cigarette lighter and radio fuse. Then with those fuses removed and the light is still illuminated, remove one fuse at a time to see if any when removed, turns off the illuminated test light. Once you find the fuse that effects the test light, you have found the circuit that has a short causing the draw. Sometimes it's not always related to a fused circuit but more often then not it is.If all fuses are removed and light stays lit then it is a direct short not related to the fuses circuit. This could be a positive wire connected to a groung wire ,body ground or engine ground. Hope this helps good luck and stay safe
