Electromagnetic Interference (EMI) and Electrical Noise
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
Some electrical components/circuits are sensitive to electromagnetic interference (EMI) or other types of electrical noise. Inspect for the following conditions:
- A misrouted harness that is too close to high voltage/high current devices such as secondary ignition components, motors, generator, etc. These components may induce electrical noise on a circuit that could interfere with normal circuit operation.
- Electrical system interference caused by a malfunctioning relay or a control module driven solenoid or switch-These conditions can cause a sharp electrical surge. Normally, the condition will occur when the malfunctioning component is operating.
- Improper installation of non-factory or aftermarket add on accessories such as lights, 2-way radios, amplifiers, electric motors, remote starters, alarm systems, cell phones, etc. These accessories may lead to interference while in use, but do not fail when the accessories are not in use. Refer to Checking Aftermarket Accessories .
- Test for an open diode across the A/C compressor clutch and for other open diodes. Some relays may contain a clamping diode.
- The generator may be allowing AC noise into the electrical system.