Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Component Testing: Introduction
Component testing procedures are provided to determine whether a component is good or bad.
Testing information for each component includes a schematic with component terminal locations and step-by-step test procedures. Component terminals are identified by:
- the circuit number of the wires that connect to that terminal,
- the wire insulation color, and
- letters or numbers that may be marked on the component.
The component connector MUST BE REMOVED before testing. To test a single circuit within the component, select that circuit under the column TO TEST. If you wish to test the complete component, perform all tests.
Connect the tester to the terminals shown in the second column and operate the component as shown in the third column.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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