Electrical Help. Problem With 2000 V6 Convertible

Discussion in 'SN95 V6 Mustang Tech' started by niconitis, Jul 2, 2013.

  1. My brand new battery keeps being drained. Probably the alternator. However, none of my power windows will roll up. The side mirror also wont work. Everything else works fine. The convertible top works but is lagging and I have to pull it a little to get it all the way up. I have checked the fuses. Could the alternator and power windows not functioning be linked? Or would the bad alternator affect all of the electronics?
  2. Do you have a digital multimeter that can read DC amps up to 10A?

    If you do, unplug one terminal from the battery and hook the meter up in series. You should have a drain of under 1A. If you have more than that, unplug fuses until you find the fuse that's drawing a lot of current. That should help you track down the shorted circuit.

    It's possible your power window switch is shorted, most likely from water dripping on it when the window is rolled down.
  3. Another option to read the current, is to use a resistor. I have access to lots of resistors, so it was easy for me. I twisted 5, 5 ohm resistors together, to make a 1 ohm resistor. Then undo one terminal, touch the resistor to the terminal and the battery, and read the voltage across the resistor. In this case, the reading will also be in amps, since Volt/1 Ohm = amps. Mine was reading about 0.16A. To me, that sounds about right, with all the electronics in a car drawing minimal current in the off state.
    A fully charged battery should read 12.7 V. With tthe car running, the alternator charges, you should read more than 13.5 V (more like 14 -14.5V)
    Another thing that can cause some of your problems, is dirty connections. Insure that your battery to cable connections is clean. Get a batter terminal cleaner (wire brush type). Remember to turn the brush in one direction only. Then, check the ground connection to the engine (and other places). Mine was right below the power steering pump. If someone says "its only ground", they do not understand that currnet needs to have a full circle pathway.
    If you have a 2 ohm resistance dirty connection, and try to draw 1 amp, there is a 2V drop right there, "robbing" voltage from where you want it - and of course as the resistance goes up form there, it only gets worse.
    I see you are in Georgia, so rusty connections should not be an issue - unless you are near the ocean. Do you know the history of the car - was it near the ocean, or from the rust belt?