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

Voltage Drop Testing The Battery (+) Cable. How To Test The Starter Motor (2001-2002 2.7L V6 Dodge Stratus, Chrysler Sebring)

In this last test, we're gonna' do a voltage drop test on the battery wire that connects to the starter motor.

Why do a voltage drop test on this wire? Because in some cases, the starter motor is OK but it isn't cranking the engine because this wire is not supplying the full amount of current that's available from the battery.

Usually, this is due to some sort of hidden corrosion blocking the delivery of all the current it can carry.

This is a pretty easy test to do an interpret using only 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 you 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 (.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 confirms that the battery cable is OK.

You can conclude your Dodge Stratus or Chrysler Sebring's starter motor 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 result tells you that a voltage drop does exist. In other words, the battery's full power is not reaching the starter motor.

The good news is that this is usually 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 2.7L Dodge Tutorials

If this tutorial was helpful, you can find a complete list of 2.7L Dodge tutorials in this index:

  1. Chrysler 2.7L Index of Articles.

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

  1. How To Test The Blower Motor (2001-2006 Dodge Stratus).
  2. How To Test The Throttle Position Sensor (2.7L V6 Chrysler).
  3. How To Test The MAP Sensor (2000-2004 2.7L Chrysler).
  4. How To Test Engine Compression (2.7L V6 Chrysler).
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