How To Test The Alternator (1993-1998 1.5L Toyota Tercel)

By: Abraham Torres-Arredondo
Created: 02 May 2022
Updated: 12 December 2022
Articl Id: 1159

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TEST 2: Testing The Continuity Of The Alternator's Output Wire

Testing The Continuity Of The Alternator's Output Wire. How To Test The Alternator (1993, 1994, 1995, 1996, 1997, 1998 1.5L Toyota Tercel)

The alternator's amperage and voltage output is delivered to the battery via a single wire.

This output wire is protected by a 100 Amp fuse. This 100 Amp fuse is found in the engine compartment fuse/relay box.

If the 100 Amp fuse is blown, the alternator's output will not reach the battery and the battery won't get charged.

So in this test step, you'll do a simple multimeter continuity test on the wire to determine if the fuse is good or blown.

If your test result reports that the wire has continuity (thus confirming the fuse is OK), your next and last test is TEST 3.

OK, let's get started:

1
Disconnect the battery negative (-) cable from the battery but leave the positive (+) cable connected to the positive (+) post.

IMPORTANT: Do not proceed to the next steps until you do this first.
2
Set your multimeter to Ohms mode.
3
Connect the red multimeter test lead to the stud shown in the photo above.

The alternator's output wire connects to the stud the arrow points to (in the photo above).
4
Connect the black multimeter test lead on the battery positive (+) terminal (at the battery).

The battery negative (-) wire must remain disconnected from the battery.
5
Your multimeter will register one of two values:

1.) Continuity (usually an Ohms value of about 0.5 Ohms).

2.) No continuity (an infinite Ohms reading (OL)).

OK, let's interpret your test results:

CASE 1: Your multimeter registered continuity (usually 0.5 Ohms). This is the correct and expected test result and it tells you that the 100 Amp fuse that protects the alternator's output wire is OK.

So far, it's looking like the alternator is bad. There's still one more test to do, go to: TEST 3: Checking The Alternator Fuse.

CASE 2: Your multimeter DID NOT register continuity, it registered OL. This test result confirms that the 100 Amp fuse that protects this wire is blown.

Your next step is to replace the 100 Amp fuse and retest.

TEST 3: Checking The ALT-S Fuse

In this test section, we'll make sure the ALT-S fuse is providing 12 Volts DC to the S terminal of your Toyota Tercel's alternator.

Depending on your Toyota Tercel's year model, the ALT-S fuse will have a different Amp rating:

On the 1993-1994 Tercel, the ALT-S fuse is a 7.5 Amp fuse.
On the 1995-1998 Tercel, the ALT-S fuse is a 5 Amp fuse.

On all 1993-1998 1.5L Toyota Tercel, the ALT-S fuse is located in the engine compartment fuse/relay box.

Let's get started:

1
Locate the ALT-S fuse.

NOTE: The ALT-S fuse is located in the engine compartment fuse box.
2
Remove the ALT-S fuse.
3
Visually inspect the fuse.
4
You'll see one of two things:

1.) The fuse is blown.

2.) The fuse IS NOT blown.

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

CASE 1: The ALT-S fuse is NOT blown. This is the correct and expected test result.

Your next step is to go to: TEST 4: Checking The GAUGE Fuse.

CASE 2: The fuse IS blown. Replace the fuse with the correct Amp rating and repeat all tests.

TEST 4: Checking The GAUGE Fuse

For our last test, we'll test the GAUGE fuse located in the interior fuse box.

This interior fuse box is located behind the left kick panel (driver side of the passenger compartment).

Depending on your Toyota Tercel's year model, the GAUGE fuse will have a different Amp rating:

On the 1993-1994 Tercel, the GAUGE fuse is a 15 Amp fuse.
On the 1995-1998 Tercel, the GAUGE fuse is a 10 Amp fuse.

These are the test steps:

1
Locate the GAUGE fuse.

NOTE: The GAUGE fuse is located in the engine compartment fuse box.
2
Remove the GAUGE of the interior fuse panel.
3
Visually inspect the fuse.
4
You'll see one of two things:

1.) The fuse is blown.

2.) The fuse IS NOT blown.

Let's analyze your test result:

CASE 1: The GAUGE fuse is NOT blown. This is the correct and expected test result.

You can conclude that the alternator is bad if you have:

Confirmed that battery voltage is below 12.5 Volts DC as the engine runs (TEST 1).
Confirmed that the 100 Amp fuse that protect the alternator's output wire is not blown (TEST 2).
Confirmed that the ALT-S fuse is not blown (TEST 3).
In this test section, you've confirmed that the GAUGE fuse is OK.

CASE 2: The fuse IS blown. Replace the fuse and repeat all tests.

If the alternator does not charge the battery, you can conclude that it's bad (and needs replacement) if you have: