TEST 1: Applying 12 Volts To The Starter Motor S Terminal
The very first thing that we're gonna' do is to manually apply 12 Volts, from your Ford Escape's battery, to the starter motor solenoid.
To be a bit more specific, we'll be applying this battery power directly to the S terminal of the starter motor solenoid.
This basically bypasses the ignition switch and lets us know right off the bat if the starter motor is OK or not.
If the starter motor is functioning correctly, then this will cause the starter motor to activate and crank the engine.
This is a very simple test but it does require that you use a jumper cable or a remote starter switch to apply power to the starter motor solenoid.
The fastest, easiest, and safest way to do this is with a remote start switch. You can take a look at this tool here: Sunpro Actron CP7853 Remote Starter Switch.
IMPORTANT: Before you perform this test remove the key from the ignition switch to prevent the engine from accidentally starting. If your Ford Escape is equipped with a standard transmission, place it in neutral.
IMPORTANT: Place your Ford Escape on jack stands if you raise it to access the starter motor!
OK, these are the test steps:
Disconnect the battery negative (-) terminal.
You'll reconnect it back in one of the following steps, for now, it's a safety precaution as you set up the test.
Attach one of the alligator-type terminals of the remote starter switch to the S terminal of the starter motor.
Reconnect the negative (-) battery cable to the battery negative post.
NOTE: Make sure that the battery cables and posts are clean.
Connect the remaining alligator-type terminal of the remote starter switch to the battery positive (+) post.
IMPORTANT: If your Ford Escape has a standard transmission, make sure it's out of gear before you make this last connection.
Activate the starter motor with your remote starter switch. As you apply these 12 Volts (to the S terminal of the starter motor), you'll get one of two results:
1) The starter will activate and will turn over the engine -OR- 2) The starter motor won't do a thing.
Let's examine your test result:
CASE 1: The starter motor cranked the engine. This test result let's you know that your Ford Escape's starter motor is OK and functioning.
If the starter motor is NOT cranking the engine when you turn the key to start it, then it's probably not receiving the activation signal from the ignition switch.
To further test this, go to the next test: TEST 2: Verifying The Start Signal.
CASE 2: The starter motor DID NOT crank the engine. This usually means that your Ford Escape's starter motor is bad and needs to be rebuilt or replaced.
I suggest 2 more tests and these are make sure that the starter motor is getting its 12 Volt signal signal and to test the battery cable (that attaches to the starter motor solenoid) for corrosion. This can be accomplished very easily with a voltage drop test.
If the above two tests confirm that the start signal IS present and there's no voltage drop on the battery cable (feeding battery power to the starter motor), then you can confidently conclude your Ford Escape's starter motor is bad and needs to be replaced.
TEST 2: Verifying The Start Signal
In this section, we're gonna' make sure that the starter motor is getting an activation signal when you turn the key to crank and start the engine.
As you're probably already aware, the starter motor has two wires connected to it. The thicker wire is the one that connects directly to the battery positive terminal.
The other wire, which is are they lighter gauge, is the one that feeds the activation signal to the starter. This wire connects to the S terminal of the starter motor solenoid.
So then, we're gonna' connect a multimeter to the S wire and see if it's feeding the start signal to the solenoid when we turn the key to crank and start the engine.
OK, these are the test steps:
Connect the red multimeter test lead to the S terminal of the starter motor.
Attach the black multimeter test lead to a clean and rust-free spot on the engine or on the vehicle frame.
I recommend that you use a battery jump start cable to ground the black multimeter test lead directly to the battery negative terminal.
Have your helper crank the engine from inside your Ford Escape.
The engine won't turn over, but the idea is to verify that the starter motor's internal solenoid is getting the 12 Volt start signal from the ignition switch (or not).
Your multimeter is going to register one of two results: Either 9 - 12 Volts DC or no voltage at all.
Let's analyze your test result:
CASE 1: The multimeter registered 9 to 12 Volts. This is the correct test result and is good news, since it lets you know that the starter motor is getting its activation signal (when you turn the key and crank the engine).
This test result eliminates the safety neutral switch and the ignition switch as being faulty. The next step is to do a voltage drop test on the starter's battery cable. For this test go to: TEST 3: Voltage Drop Testing The Battery (+) Cable.
CASE 2: The multimeter DID NOT register 9 to 12 Volts. This result tells you that the starter motor is not getting its activation signal. Without it, the starter motor will not crank the engine when you turn the key to crank and start the engine.
Usually, when the starter's activation signal is not present on the wire that connects to the starter solenoid's S terminal, it's usually because:
- The ignition switch is faulty.
- The starter relay is defective.
- The neutral safety switch is faulty or misaligned.
Although it's beyond the scope of this article to test the neutral safety switch, the starter relay, or the ignition switch, you have eliminated the starter motor as defective.