How To Test The Starter Motor (1992-1994 3.0L Ford Ranger)

By: Abraham Torres-Arredondo
Created: 19 December 2017
Updated: 16 March 2024
Articl Id: 690

Page 3 of 3

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

Voltage Drop Testing The Battery (+) Cable. How To Test The Starter Motor (1992, 1993, 1994 3.0L Ford Ranger, Aerostar, And Mazda B3000)

If you've reached this point, you have confirmed that:

The starter motor is getting a 'start' signal (TEST 2) but when you turn the key to crank the engine, the starter motor doesn't do anything.

There's a good chance that the starter motor is getting the battery's full power to turn the engine over.

We can find out by doing a simple voltage drop test (with the multimeter in Volts mode) on the battery cable that connects to the starter motor's solenoid.

This is a very easy test and it'll let your know if hidden corrosion is keeping your Ford Ranger's starter motor from cranking the engine.

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
Place your multimeter in Volts DC mode.
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
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
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
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 tells you that the starter motor is receiving all of the battery voltage and amperage it needs to crank the your Ford Ranger's engine.

You can conclude your Ford Ranger's starter motor is defective if you have:

Confirmed that the starter motor doesn't work when you apply power to the S terminal wire of the starter motor (TEST 1).
Confirmed that the starter motor is receiving the crank signal (TEST 2).
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:

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.
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 and that the battery's full power is not 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.