Starter; Testing; Starting System Voltage Drop Tests; Starter Feed Circuit - Chevrolet Trailblazer Service Manual

Starter

Testing

Starting System Voltage Drop Tests

NOTE: The battery must be in good condition and fully charged prior to performing this
test.
There are three area of the starter motor circuits that voltage drop test can be performed
on. These include:
The starter feed circuit
The starter ground circuit
The starter solenoid.

Starter Feed Circuit

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of a voltmeter to the positive terminal of the battery.
4. Connect the negative lead of a voltmeter to the starter B+ terminal.
5. Turn the ignition key to the START position and note the voltage displayed on the
voltmeter.
Ideally, there should be no more than 0.1 volt drop for each connection
displayed on the voltmeter. No voltage should be consumed by the vehicle
wiring
A. If the battery cable connects directly to the starter motor there
B. If the vehicle uses a starter solenoid between the battery and the
Starter Ground Circuit
1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of the voltmeter to the case of the starter motor.
4. Connect the negative lead of the voltmeter to the negative terminal of the battery.
5. Turn the ignition key to the START position and note the voltage displayed on the
voltmeter.
Ideally, there should be no more than 0.1 volt drop for each connection
displayed on the voltmeter. No voltage should be consumed by the vehicle
wiring
A. If the battery cable connects directly to the starter motor there
should be no more than a 0.2 volt drop measured
starter motor terminal there should be no more than 0.4 volt
displayed on the voltmeter
should be no more than a 0.2 volt drop measured.