YES! Another noob Volvo owner/poster scouring the collective knowledge base for help with a repair issue.(BTW, I did look through as many search topics as I could think of and came up empty.) I just picked up my first Volvo, a 1990 240 DL wagon, which came with its ownset ofquirks. I should have realized when I saw a new battery under the hood that there might be electrical issues. When left unstarted for more than 12 hours or so, the battery drains completely. After charging it back up, I tried removing fuses, one at a time, and checking for a spark on the negative battery post. No luck, as there was a spark every time (even with the clock fuse out). When I tap the post clamp to the poston the I can actually hear the click of a short somewhere under the hood (in addition to the spark on the post), but am fairly clueless about where and how to start looking for the location. Does anyone know of a place this happens more often than not? It seems to be coming from somewhere in the area of the fuel injectors, but I can't locate it. I just bought my first multimeter, and kind of understand the concept of looking for a lack of continuity in a circuit, but I'm not sure where to start. In the mean time, I'm disconnecting the negative battery terminal when I am away from the car for more than eight hours or so. Not too convenient, but better than finding a dead battery.
Thank you in advance for any and all suggestions.

 

What you have is (unwanted)current flow. Hopefully you have the ability to measure amps with your meter - usually it requires moving the positive probe to another spot and selecting "A" (amps). You can then make in-series current measurements.

Place one probe on the neg battery terminal, the other on the neg battery wire - current should be less than 100mA (you'll probably see more).

Then go through the fuse panel, subsituting your probes for the fuse. This should help you isolate the drain.

 

Thanks Bubba, but it doesn't seem to be something that goes through the fuses. That must narrow the search though ... I appreciate your help.

 

Be careful of unfused electrical shorts -- fire under the hood.

There are a few unfused circuits. The starter, the alternator, the headlights. It could be the voltage regulator in the alternator.

Does the battery warning light come on while cranking the engine?

I would start by disconnecting the alternator. Then see what the current drain is.

Post back.

 

Thanks Goose.
Looks like the current draw is the same with the alternator disconnected. Also, the battery warning light does turn on when I crank the engine. I'll hook up the alternator again, and maybe try again with the starter disconnected?
Again, thank you so much for the help.

 

Update: It seems the short was, as it sounded, coming from the fuel injection system. Unable to locate the exact source of trouble, I took the car to a mechanic who had a very good idea. Instead of spending a week checking every little wire on the unit, we decided to put a switch on the circuit, located on the dash. The fuel suystem was always on and drawing juice, but now I can turn it off when I turn off the car. I'm going to attach a string from the switch to a hook for my keychain so I don't forget to turn the switch off. I got off a lot cheaper than I figured I might have.