I just had a new battery put in my 850 (1994). After about a week of mainly sitting in the driveway, the battery is totally dead. The mechanic who put the battery in said it might be the window switch which was giving me some problems. I've now turned it to the "off" position on the console. How do I test to see what's draining it? Radio's off, lights are off, nothing's on. Thanks

 

1. Remove the negative side battery cable from the negative battery terminal.
2. Connect the black wire to the com input on the multimeter and the red wire to the 10A or 20A input on the multimeter. the meter needs to be able to read at least a 2 or 3 amps for this test to work. Connecting the red wire to the mA input on the multimeter won't work and could damage the meter.
3. Attach a multimeter(set the dial on the multimeter to measure Amps as per multimeters instructions) between the negative cable and the negative battery post. Wait a few seconds to several minutes for the car to go into sleep mode - i.e. when you make the contact with the ammeter, the cars computer systems "wake up". After a bit of time they will go back to "sleep".
4. If the ammeter is reading over 25-50 milliamps, something is using too much battery power.
5. Go to the fuse panel(s) and remove fuses, one at a time. Pull the main fuses (higher amp ratings)last. Perform the same steps for relays found in the fuse panel. Sometimes relay contacts can fail to release causing a drain. Be sure to observe the ammeter after pulling each fuse or relay.
6. Watch for the ammeter to drop to acceptable drain. The fuse that reduces the drain is the draw. Consult the owners' manual or service manual to find what circuits are on that fuse.
7. Check each device (circuit) on that fuse. Stop each lamp, heater, etc. to find the drain.
8. Repeat steps 1&2 to test your repair. The ammeter will tell you exact numbers.
9. If you still can't find it and the draw on the meter is excessive don't forget to take the battery lead off the alternator. Every once in a while an alternator will go bad where it will charge a battery properly but when turned off it will allow current to reverse and drain the battery. This kind of failure where one of the diodes goes bad will not turn on any idiot light.

 

Check the 'Helpful Information' section of this forum for issues like this. Here are the steps for finding the drain.

https://volvoforums.com/forum/volvo-...g-101-a-42655/

 

Dear Kiss and Box,

Thanks for the tips. I tried the least complicated first: namely, the solution regarding the glove box light. And yes, the door wasn't closing tight enough so that the light stayed on. I put in some duct tape and the nose guards on eye glasses you can get from the dime store to "raise" the area of the contact point last night after charging the battery. This morning I'll check to see if that worked. By the way, will an ordinary AC/DC meter do the job or must the meter be a load tester? Thanks both.

 

A multimeter and a load tester are two different tools. The multimeter is just a meter that reads a couple different values, Volts, Amps and Ohms and may have a continuity check separate from the Ohms meter that is just a go / no go by means of a buzzer.
A load tester usually has just a volt meter on it so you can see what voltage the battery has as it is drained by the tester.

 

Thanks, Kiss.