TEST 3: Voltage Drop Testing The Battery (+) Cable

Voltage Drop Testing The Battery (+) Cable. How To Test The Starter Motor (2001-2004 2.0L Ford Escape)

In some cases, even though the battery positive cable terminal and battery positive post are clean and look corrosion-free, there is still some hidden corrosion that is preventing the full amount of battery current from reaching the starter.

When this happens, the starter just makes a clicking sound and doesn't turn over the engine.

In the majority of cases, when this happens, it's due to hidden corrosion on the battery cable that connects the starter motor to the battery positive post.

The best way to find out if the cable has a problem is by doing a simple and easy voltage drop test with a multimeter.

IMPORTANT: Don't disconnect the battery cable from the starter motor's solenoid. In the illustration the battery cable is disconnected from the starter motor just to make it easier to show the multimeter test connections.

Let's get testing:

  1. 1

    Place your multimeter in Volts DC mode.

  2. 2

    Attach the black multimeter test lead to the center of the positive (+) battery terminal.

    If the positive battery post isn't clean, clean a spot right on the top of it. It's important that the multimeter lead make contact right in the center of the positive battery post.

  3. 3

    Connect the black multimeter test lead to the center of the stud to which the big battery cable attaches to on the starter solenoid.

  4. 4

    Have your helper crank the engine even though the starter motor isn't cranking the engine.

    This is important, since a voltage drop test has to be done while the component in question is working (or trying to work).

  5. 5

    If all is good (no voltage drop), your multimeter will register 0 Volts (0.5 Volts is still 0 Volts).

    If there's a voltage drop (which is bad), your multimeter will register voltage (usually above 7 Volts DC.)

Let's take a look at what your results mean:

CASE 1: Your multimeter registered 0 Volts (no voltage drop). This is the correct test result and lets you know that the battery cable, that connects the battery positive post to the starter, is OK.

You can also conclude that the starter motor is receiving the full amount of battery current it needs to start.

Now, you can conclude that the starter motor, on your 2.0L Ford Escape is defective, if you have:

  1. Confirmed that the starter motor doesn't work when you apply power to the S terminal wire of the starter motor (TEST 1).
  2. Confirmed that the starter motor is receiving the crank signal (TEST 2).
  3. In this test step you have confirmed that no voltage drop exists on the battery positive cable.

Replacing the starter motor should solve your no crank condition.

I'm going to make two more recommendations to you:

  1. Before removing the starter motor, manually turn the engine using a 1/2 ratchet and the appropriate socket. This is to make sure that the engine or the A/C compressor have not locked up and causing the no crank condition.
  2. Bench test the starter motor after removing it. This is a super easy test to do and this tutorial will help: Bench Testing The Starter Motor.

CASE 2: Your multimeter registered 5 Volts or more. This test result lets you know that there's a problem with the battery cable that connects the starter motor to the battery positive post. To be a bit more specific, this voltage drop test result lets you know that the full amount of available battery current isn't reaching the starter motor.

The good news is that this can easily be corrected, since a voltage drop is always caused by some sort of corrosion issue on the battery positive cable or terminals or the battery positive post.

The solution is to thoroughly clean the battery positive post and the battery positive terminal (both the end that attaches to the battery positive post and the end the connects to the starter motor's battery (+) cable stud.

After cleaning, try cranking the engine. If it cranks and starts, no further testing is required.

More 2.0L Ford Escape Tutorials

You can find a complete list of 2.0L Ford Escape tutorials in this index:

  1. Ford 2.0L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

  1. How To Test The Throttle Position Sensor (2001-2004 2.0L Ford Escape).
  2. Oxygen Sensor Heater Test -P0135 (2001-2004 2.0L Ford Escape).
  3. How To Test Engine Compression (2.0L Ford).
  4. How To Test The Fuel Injectors (2001-2004 2.0L Ford Escape).
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Ford Vehicles:

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