1994 Volvo 850 Turbo BATTERY DRAIN

[lovevolvosalot]

To anyone who has any input I would appreciate it greatly. I bought a project car from a lady who told me that the cars only problem was electrical, so far this seems to be true. The car sat for about a year and a half after she stopped driving because of a problem with the car dying every time she turned it off. She said she had to jump start it every time they used it because something was draining the battery. I towed the car home and put a battery in it, left the car for about 2 hours while I worked under the hood, when I tried to start it, it did not start. I figured ok its been sitting that long I'm not surprised it'll need a lot of general maintenance that was missed. I then took the battery out of that car, and put it back into my running car, only to find out it was totally dead.

I'm hoping to get some insight from people who have dealt with electrical problems on these cars. I will post things as I test them, but one thing you should know is that when a battery is hooked up to the car even without the key in the ignition, the heater blower motor still works. But none of the other options like windows, seats, or mirrors work?! Is the battery staying live somehow even with the key out of the ignition, and if so, why just the heater blower motor? A ground, a relay? Yeah, I'm swamped. I'm beginning to wish the car some mechanical issue instead! If you need more information feel free to ask, I'd really appreciate it. Thanks in advance!

[Ozark Lee]

I will post things as I test them, but one thing you should know is that when a battery is hooked up to the car even without the key in the ignition, the heater blower motor still works.

When you say it "still works" what exactly are you saying? Does it not shut off when the key is removed?

If so, and if you have the Electronic Climate Control unit then you have a bad power stage (The power stage is often called a blower resistor).

Please elaborate a bit more about the blower motor behaviour.

Beyond the blower motor - which will quickly kill your battery unless you remove fuse number 5 - the procedure to test for excessive parasitic draw is to remove a battery cable and put a DC Ammeter in line between the cable and the battery terminal. From there (after the interior lights have timed out) start pulling fuses until you see the meter reading drop. With that fuse number you can then start tracing the wiring to the given devices that are run by that fuse.

Normal parasitic draw is under 0.1 amps - on mine without a bunch of aftermarket junk installed it tends to run around 0.03 amps.

...Lee